Context-sensitive handling of interruptions

[0001] This application claims the benefit of U.S. Provisional Application No. 61/785,805, filed on Mar. 14, 2013, entitled CONTEXT-SENSITIVE HANDLING OF INTERRUPTIONS, which is hereby incorporated by reference in its entity for all purposes.

[0002] The disclosed embodiments relate generally to digital assistants, and more specifically, to digital assistants that intelligently handle user-initiated and/or system-initiated interruptions based on the current context.

[0003] Just like human personal assistants, digital assistants or virtual assistants can perform requested tasks and provide requested advice, information, or services. An assistant's ability to fulfill a user's request is dependent on the assistant's correct comprehension of the request or instructions. Recent advances in natural language processing have enabled users to interact with digital assistants using natural language, in spoken or textual forms, rather than employing a conventional user interface (e.g., menus or programmed commands). Such digital assistants can interpret the user's input to infer the user's intent, translate the inferred intent into actionable tasks and parameters, execute operations or deploy services to perform the tasks, and produce outputs that are intelligible to the user. Ideally, the outputs produced by a digital assistant should fulfill the user's intent expressed during the natural language interaction between the user and the digital assistant.

[0004] The ability of a digital assistant system to produce satisfactory responses to user requests depends on the natural language processing, knowledge base, and artificial intelligence implemented by the system. A well-designed response procedure can improve a user's experience in interacting with the system and promote the user's confidence in the system's services and capabilities.

[0005] Many digital assistants can deliver responses in the form of speech outputs. For example, in some circumstance, speech outputs include one or more turn-by-turn directions (e.g., “Turn left on Whipple Avenue”) read aloud to the user by a text-to-speech engine. These speech outputs are generally provided at a predetermined time (e.g., ¼ of a mile before reaching Whipple Avenue) or immediately (e.g., in the case of a response to a question such as “What time is it?”). A disadvantage of these digital assistant response procedures is speech outputs may be provided at inopportune times, such as by interrupting a user who is speaking into the device during a phone conversation or issuing new requests to the digital assistant. Interruptions that provide non-urgent information are frustrating and inconvenient for users. In addition, while possible to listen to two different audio streams, it is difficult for people to listen while they are, themselves, talking. Therefore, when a digital assistant attempts to deliver speech outputs while a user is speaking, it inhibits the user's ability to understand those speech outputs.

[0006] Accordingly, there is a need for methods of operating a digital assistant that intelligently and intuitively determine whether to provide a speech output. In particular, there is a need for methods of operating a digital assistant that determine whether the user is speaking and whether the speech output is urgent enough to warrant an interruption.

[0007] The embodiments described below offer an improved method for providing speech outputs to a user. In particular, in some embodiments, a digital assistant waits a predetermined amount of time after the user has finished speaking before providing a speech output. Of course, some speech outputs carry greater urgency than others. For example, when a digital assistant is scheduled to inform a user that they will need to turn left on Whipple Avenue in 10 seconds, the user must receive the information prior to missing the turn. In other circumstances, the user may have asked the digital assistant to inform him or her of the Knicks' score at the end of each game. Providing a speech output indicating the latest Knicks' score is less urgent. Therefore, in some embodiments, the predetermined amount of time is based on the urgency of the speech output. For example, in some embodiments, the default predetermined time is one second (e.g., a long enough time to be reasonably sure that the user has finished speaking), whereas a fairly urgent output (“Turn left in ¼ mile”) will be provided half of a second after the user has finished speaking (e.g., an amount of time that corresponds to a pause in speech). In some circumstances, the speech output is absolutely urgent (“Turn left now”) and the predetermined amount of time is zero (e.g., the digital assistant barges-in and interrupts the user).

[0008] The disclosed embodiments improve on speech output response procedures and methods by interrupting a user who is speaking only with urgent messages. These embodiments are motivated by the general observation that a user will have some ability to understand two sets of audio outputs, based on the user's ability to contextualize the two audio outputs without necessarily understanding every word. On the other hand, the user will have a very difficult time understanding an audio output while contemporaneously speaking themselves. Therefore, the disclosed embodiments may result in greater user comprehension of speech outputs assistants and a more satisfying user experience.

[0009] The embodiments disclosed herein provide methods, systems, computer readable storage medium and user interfaces for a digital assistant to intelligently and dynamically determine whether to provide a speech output. The method includes receiving a speech output to be provided to a user of a device and determining if the device is currently receiving speech input from a user. The method further includes, upon determining that the device is not currently receiving speech input from the user, providing the speech output to the user. On the other hand, upon determining that the device is receiving speech input from the user, the method further includes determining if provision of the speech output is urgent. When the speech output is urgent, the speech output is provided to the user. When the speech output is not urgent, provision of the speech output to the user is stayed (e.g., at least temporarily).

[0010] In some embodiments, the method further includes, prior to receiving the speech output, receiving a request from the user to perform a digital assistant task. In some embodiments, the method further includes, prior to receiving the speech output, sending the request to a digital assistant server. In some embodiments, the speech output is received from the server in response to the request. In some embodiments, receiving the speech output includes generating the speech output at the device.

[0011] In some embodiments, the method further includes, upon determining that provision of the speech output is urgent, providing the speech output to the user without delay.

[0012] In some embodiments, the device is a telephone, and determining if the device is currently receiving speech input from the user includes determining if the user is participating in a telephone conversation with a remote user.

[0013] In some embodiments, upon determining that the device is not currently receiving speech input from the user, audio data received from the remote user and the speech output to the user are provided contemporaneously without staying provision of the speech output due to the received audio data.

[0014] In some embodiments, the method further includes, during a telephone conversation with the remote user, transmitting a request to the remote user to request the avoidance of digital assistant interruptions.

[0015] In some embodiments, the method further includes, upon determining that the device is no longer receiving speech input from the user, providing the speech output to the user. In some embodiments, determining that the device is no longer receiving speech input from the user includes determining that a predefined amount of time has elapsed between a time of a last speech input and a current time. In some embodiments, the predefined amount of time is a function of a measure of the urgency of the speech output. In some embodiments, the predetermined amount of time is a monotonically decreasing function of the measure of the urgency of the speech output, thereby providing speech outputs with a greater measure of urgency in a lesser amount of time.

[0016] In some embodiments, determining if the device is currently receiving speech input from the user includes determining if a last speech input was received within a predetermined period of time. In some embodiments, the predetermined period of time is a function of a measure of a urgency of the output.

[0017] In some embodiments, the method further includes, determining if the output meets message skipping criteria and, upon determining that the speech output meets message skipping criteria, forgoing providing the output altogether. In some embodiments, the message skipping criteria are met when the measure of the urgency is lower than a predefined threshold. In some embodiments, the message skipping criteria are met when the speech output is a navigational command in a set of turn-by-turn directions and the device is scheduled to give a corresponding navigational command at a later time.

[0018] In some embodiments, the method further includes, during provision of the speech output receiving speech input from the user and discontinuing speech output. In some embodiments, the method further includes, determining if completion criteria corresponding to the speech output have been met. In such embodiments, the method further includes, upon determining that the completion criteria have not been met, staying at least part of the speech output for later time. In such embodiments, the method further includes, upon determining that the completion criteria have been met, forgoing output of the remainder of the speech output altogether. In some embodiments, the completion criteria are met when a predefined percentage of the speech output has already been provided to the user. In some embodiments, the predefined percentage of speech output is selected from the group consisting of: 50%, 60%, 70%, and 80%.

[0019] In some embodiments, the device includes a display. In such embodiments, the method further includes, upon determining that provision of the speech output is not urgent, providing a displayed output corresponding to the speech output.

[0020] In some embodiments, the method further includes, when the device is in a special mode of operation, providing the speech output without delay. In some embodiments, the special mode of operation is one or more of the group consisting of a hold mode of operation and a mute mode of operation.

[0021] In some embodiments, when the speech output meets user-configurable criteria for immediate provision, providing the speech output without delay. In such embodiments, the user-configurable criteria are met when the device receives an electronic message (e.g., an SMS or e-mail message) from a person that the user has previously identified as a very important person. In such embodiments, the user-configurable criteria are met when the device receives a stock price update and wherein the user has previously configured the device to provide the stock price update immediately.

[0022] In some embodiments, when the device is in a do-not-disturb mode of operation, provision of the speech output is forgone.

[0023] The details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims.

[0031] Like reference numerals refer to corresponding parts throughout the drawings.

[0032] FIG. 1 is a block diagram of an operating environment 100 of a digital assistant according to some embodiments. The terms “digital assistant,” “virtual assistant,” “intelligent automated assistant,” or “automatic digital assistant,” refer to any information processing system that interprets natural language input in spoken and/or textual form to infer user intent, and performs actions based on the inferred user intent. For example, to act on a inferred user intent, the system can perform one or more of the following: identifying a task flow with steps and parameters designed to accomplish the inferred user intent, inputting specific requirements from the inferred user intent into the task flow; executing the task flow by invoking programs, methods, services, APIs, or the like; and generating output responses to the user in an audible (e.g., speech) and/or visual form.

[0033] Specifically, a digital assistant is capable of accepting a user request at least partially in the form of a natural language command, request, statement, narrative, and/or inquiry. Typically, the user request seeks either an informational answer or performance of a task by the digital assistant. A satisfactory response to the user request is either provision of the requested informational answer, performance of the requested task, or a combination of the two. For example, a user may ask the digital assistant a question, such as “Where am I right now?” Based on the user's current location, the digital assistant may answer, “You are in Central Park near the west gate.” The user may also request the performance of a task, for example, “Please invite my friends to my girlfriend's birthday party next week.” In response, the digital assistant may acknowledge the request by saying “Yes, right away,” and then send a suitable calendar invite on behalf of the user to each of the user’ friends listed in the user's electronic address book. During performance of a requested task, the digital assistant sometimes interacts with the user in a continuous dialogue involving multiple exchanges of information over an extended period of time. There are numerous other ways of interacting with a digital assistant to request information or performance of various tasks. In addition to providing verbal responses and taking programmed actions, the digital assistant also provides responses in other visual or audio forms, e.g., as text, alerts, music, videos, animations, etc.

[0034] An example of a digital assistant is described in Applicant's U.S. Utility application Ser. No. 12/987,982 for “Intelligent Automated Assistant,” filed Jan. 10, 2011, the entire disclosure of which is incorporated herein by reference.

[0035] As shown in FIG. 1, in some embodiments, a digital assistant is implemented according to a client-server model. The digital assistant includes a client-side portion 102a, 102b (hereafter “DA client 102”) executed on a user device 104a, 104b, and a server-side portion 106 (hereafter “DA server 106”) executed on a server system 108. The DA client 102 communicates with the DA server 106 through one or more networks 110. The DA client 102 provides client-side functionalities such as user-facing input and output processing and communications with the DA-server 106. The DA server 106 provides server-side functionalities for any number of DA-clients 102 each residing on a respective user device 104.

[0036] In some embodiments, the DA server 106 includes a client-facing I/O interface 112, one or more processing modules 114, data and models 116, and an I/O interface to external services 118. The client-facing I/O interface facilitates the client-facing input and output processing for the digital assistant server 106. The one or more processing modules 114 utilize the data and models 116 to determine the user's intent based on natural language input and perform task execution based on inferred user intent. In some embodiments, the DA-server 106 communicates with external services 120 through the network(s) 110 for task completion or information acquisition. The I/O interface to external services 118 facilitates such communications.

[0037] Examples of the user device 104 include, but are not limited to, a handheld computer, a personal digital assistant (PDA), a tablet computer, a laptop computer, a desktop computer, a cellular telephone, a smart phone, an enhanced general packet radio service (EGPRS) mobile phone, a media player, a navigation device, a game console, a television, a remote control, or a combination of any two or more of these data processing devices or other data processing devices. More details on the user device 104 are provided in reference to an exemplary user device 104 shown in FIG. 2.

[0038] Examples of the communication network(s) 110 include local area networks (“LAN”) and wide area networks (“WAN”), e.g., the Internet. The communication network(s) 110 may be implemented using any known network protocol, including various wired or wireless protocols, such as e.g., Ethernet, Universal Serial Bus (USB), FIREWIRE, Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Wi-Fi, voice over Internet Protocol (VoIP), Wi-MAX, or any other suitable communication protocol.

[0039] The server system 108 is implemented on one or more standalone data processing apparatus or a distributed network of computers. In some embodiments, the server system 108 also employs various virtual devices and/or services of third party service providers (e.g., third-party cloud service providers) to provide the underlying computing resources and/or infrastructure resources of the server system 108.

[0040] Although the digital assistant shown in FIG. 1 includes both a client-side portion (e.g., the DA-client 102) and a server-side portion (e.g., the DA-server 106), in some embodiments, the functions of a digital assistant is implemented as a standalone application installed on a user device. In addition, the divisions of functionalities between the client and server portions of the digital assistant can vary in different embodiments. For example, in some embodiments, the DA client is a thin-client that provides only user-facing input and output processing functions, and delegates all other functionalities of the digital assistant to a backend server.

[0041] FIG. 2 is a block diagram of a user-device 104 in accordance with some embodiments. The user device 104 includes a memory interface 202, one or more processors 204, and a peripherals interface 206. The various components in the user device 104 are coupled by one or more communication buses or signal lines. The user device 104 includes various sensors, subsystems, and peripheral devices that are coupled to the peripherals interface 206. The sensors, subsystems, and peripheral devices gather information and/or facilitate various functionalities of the user device 104.

[0042] For example, a motion sensor 210, a light sensor 212, and a proximity sensor 214 arc coupled to the peripherals interface 206 to facilitate orientation, light, and proximity sensing functions. One or more other sensors 216, such as a positioning system (e.g., GPS receiver), a temperature sensor, a biometric sensor, a gyro, a compass, an accelerometer, and the like, are also connected to the peripherals interface 206, to facilitate related functionalities.

[0043] In some embodiments, a camera subsystem 220 and an optical sensor 222 are utilized to facilitate camera functions, such as taking photographs and recording video clips. Communication functions are facilitated through one or more wired and/or wireless communication subsystems 224, which can include various communication ports, radio frequency receivers and transmitters, and/or optical (e.g., infrared) receivers and transmitters. An audio subsystem 226 is coupled to speakers 228 and a microphone 230 to facilitate voice-enabled functions, such as voice recognition, voice replication, digital recording, and telephony functions.

[0044] In some embodiments, an I/O subsystem 240 is also coupled to the peripheral interface 206. The I/O subsystem 240 includes a touch screen controller 242 and/or other input controller(s) 244. The touch-screen controller 242 is coupled to a touch screen 246. The touch screen 246 and the touch screen controller 242 can, for example, detect contact and movement or break thereof using any of a plurality of touch sensitivity technologies, such as capacitive, resistive, infrared, surface acoustic wave technologies, proximity sensor arrays, and the like. The other input controller(s) 244 can be coupled to other input/control devices 248, such as one or more buttons, rocker switches, thumb-wheel, infrared port, USB port, and/or a pointer device such as a stylus.

[0045] In some embodiments, the memory interface 202 is coupled to memory 250. The memory 250 can include high-speed random access memory and/or non-volatile memory, such as one or more magnetic disk storage devices, one or more optical storage devices, and/or flash memory (e.g., NAND, NOR).

[0046] In some embodiments, the memory 250 stores an operating system 252, a communication module 254, a user interface module 256, a sensor processing module 258, a phone module 260, and applications 262. The operating system 252 includes instructions for handling basic system services and for performing hardware dependent tasks. The communication module 254 facilitates communicating with one or more additional devices, one or more computers and/or one or more servers. The user interface module 256 facilitates graphic user interface processing and output processing using other output channels (e.g., speakers). The sensor processing module 258 facilitates sensor-related processing and functions. The phone module 260 facilitates phone-related processes and functions. The application module 262 facilitates various functionalities of user applications, such as electronic-messaging, web browsing, media processing, Navigation, imaging and/or other processes and functions.

[0047] As described in this specification, the memory 250 also stores client-side digital assistant instructions (e.g., in a digital assistant client module 264) and various user data 266 (e.g., user-specific vocabulary data, preference data, and/or other data such as the user's electronic address book, to-do lists, shopping lists, etc.) to provide the client-side functionalities of the digital assistant.

[0048] In various embodiments, the digital assistant client module 264 is capable of accepting voice input (e.g., speech input), text input, touch input, and/or gestural input through various user interfaces (e.g., the I/O subsystem 244) of the user device 104. The digital assistant client module 264 is also capable of providing output in audio (e.g., speech output), visual, and/or tactile forms. For example, output can be provided as voice, sound, alerts, text messages, menus, graphics, videos, animations, vibrations, and/or combinations of two or more of the above. During operation, the digital assistant client module 264 communicates with the digital assistant server using the communication subsystems 224.

[0049] In some embodiments, the digital assistant client module 264 utilizes the various sensors, subsystems and peripheral devices to gather additional information from the surrounding environment of the user device 104 to establish a context associated with a user, the current user interaction, and/or the current user input. In some embodiments, the digital assistant client module 264 provides the context information or a subset thereof with the user input to the digital assistant server to help infer the user's intent. In some embodiments, the digital assistant also uses the context information to determine how to prepare and delivery outputs to the user.

[0050] In some embodiments, the context information that accompanies the user input includes sensor information, e.g., lighting, ambient noise, ambient temperature, images or videos of the surrounding environment, etc. In some embodiments, the context information also includes the physical state of the device, e.g., device orientation, device location, device temperature, power level, speed, acceleration, motion patterns, cellular signals strength, etc. In some embodiments, information related to the software state of the user device 104, e.g., running processes, installed programs, past and present network activities, background services, error logs, resources usage, etc., of the user device 104 are provided to the digital assistant server as context information associated with a user input.

[0051] In some embodiments, the DA client module 264 selectively provides information (e.g., user data 266) stored on the user device 104 in response to requests from the digital assistant server. In some embodiments, the digital assistant client module 264 also elicits additional input from the user via a natural language dialogue or other user interfaces upon request by the digital assistant server 106. The digital assistant client module 264 passes the additional input to the digital assistant server 106 to help the digital assistant server 106 in intent deduction and/or fulfillment of the user's intent expressed in the user request.

[0052] In various embodiments, the memory 250 includes additional instructions or fewer instructions. Furthermore, various functions of the user device 104 may be implemented in hardware and/or in firmware, including in one or more signal processing and/or application specific integrated circuits.

[0053] FIG. 3A is a block diagram of an example digital assistant system 300 in accordance with some embodiments. In some embodiments, the digital assistant system 300 is implemented on a standalone computer system. In some embodiments, the digital assistant system 300 is distributed across multiple computers. In some embodiments, some of the modules and functions of the digital assistant are divided into a server portion and a client portion, where the client portion resides on a user device (e.g., the user device 104) and communicates with the server portion (e.g., the server system 108) through one or more networks, e.g., as shown in FIG. 1. In some embodiments, the digital assistant system 300 is an embodiment of the server system 108 (and/or the digital assistant server 106) shown in FIG. 1. It should be noted that the digital assistant system 300 is only one example of a digital assistant system, and that the digital assistant system 300 may have more or fewer components than shown, may combine two or more components, or may have a different configuration or arrangement of the components. The various components shown in FIG. 3A may be implemented in hardware, software instructions for execution by one or more processors, firmware, including one or more signal processing and/or application specific integrated circuits, or a combination of thereof.

[0054] The digital assistant system 300 includes memory 302, one or more processors 304, an input/output (I/O) interface 306, and a network communications interface 308. These components communicate with one another over one or more communication buses or signal lines 310.

[0055] In some embodiments, the memory 302 includes a non-transitory computer readable medium, such as high-speed random access memory and/or a non-volatile computer readable storage medium (e.g., one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices).

[0056] In some embodiments, the I/O interface 306 couples input/output devices 316 of the digital assistant system 300, such as displays, a keyboards, touch screens, and microphones, to the user interface module 322. The I/O interface 306, in conjunction with the user interface module 322, receive user inputs (e.g., voice input, keyboard inputs, touch inputs, etc.) and process them accordingly. In some embodiments, e.g., when the digital assistant is implemented on a standalone user device, the digital assistant system 300 includes any of the components and I/O and communication interfaces described with respect to the user device 104 in FIG. 2. In some embodiments, the digital assistant system 300 represents the server portion of a digital assistant implementation, and interacts with the user through a client-side portion residing on a user device (e.g., the user device 104 shown in FIG. 2).

[0057] In some embodiments, the network communications interface 308 includes wired communication port(s) 312 and/or wireless transmission and reception circuitry 314. The wired communication port(s) receive and send communication signals via one or more wired interfaces, e.g., Ethernet, Universal Serial Bus (USB), FIREWIRE, etc. The wireless circuitry 314 receives and sends RF signals and/or optical signals from/to communications networks and other communications devices. The wireless communications may use any of a plurality of communications standards, protocols and technologies, such as GSM, EDGE, CDMA, TDMA, Bluetooth, Wi-Fi, VoIP, Wi-MAX, or any other suitable communication protocol. The network communications interface 308 enables communication between the digital assistant system 300 with networks, such as the Internet, an Intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices.

[0058] In some embodiments, memory 302, or the computer readable storage media of memory 302, stores programs, modules, instructions, and data structures including all or a subset of: an operating system 318, a communications module 320, a user interface module 322, one or more applications 324, and a digital assistant module 326. The one or more processors 304 execute these programs, modules, and instructions, and reads/writes from/to the data structures.

[0059] The operating system 318 (e.g., Darwin, RTXC, LINUX, UNIX, OS X, WINDOWS, or an embedded operating system such as VxWorks) includes various software components and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communications between various hardware, firmware, and software components.

[0060] The communications module 320 facilitates communications between the digital assistant system 300 with other devices over the network communications interface 308. For example, the communication module 320 may communicate with the communication interface 254 of the device 104 shown in FIG. 2. The communications module 320 also includes various components for handling data received by the wireless circuitry 314 and/or wired communications port 312.

[0061] The user interface module 322 receives commands and/or inputs from a user via the I/O interface 306 (e.g., from a keyboard, touch screen, pointing device, controller, and/or microphone), and generates user interface objects on a display. The user interface module 322 also prepares and delivers outputs (e.g., speech, sound, animation, text, icons, vibrations, haptic feedback, and light, etc.) to the user via the I/O interface 306 (e.g., through displays, audio channels, speakers, and touch-pads, etc.).

[0062] The applications 324 include programs and/or modules that are configured to be executed by the one or more processors 304. For example, if the digital assistant system is implemented on a standalone user device, the applications 324 may include user applications, such as games, a calendar application, a navigation application, or an email application. If the digital assistant system 300 is implemented on a server farm, the applications 324 may include resource management applications, diagnostic applications, or scheduling applications, for example.

[0063] The memory 302 also stores the digital assistant module (or the server portion of a digital assistant) 326. In some embodiments, the digital assistant module 326 includes the following sub-modules, or a subset or superset thereof: an input/output processing module 328, a speech-to-text (STT) processing module 330, a natural language processing module 332, a dialogue flow processing module 334, a task flow processing module 336, a service processing module 338, and an interruption handling module 340. Each of these modules has access to one or more of the following data and models of the digital assistant 326, or a subset or superset thereof: ontology 360, vocabulary index 344, user data 348, task flow models 354, service models 356, and priority parameters database 358.

[0064] In some embodiments, using the processing modules, data, and models implemented in the digital assistant module 326, the digital assistant performs at least some of the following: identifying a user's intent expressed in a natural language input received from the user; actively eliciting and obtaining information needed to fully infer the user's intent (e.g., by disambiguating words, names, intentions, etc.); determining the task flow for fulfilling the inferred intent; and executing the task flow to fulfill the inferred intent. In this specifications, more details regarding the interruption handling module and its use of the priority parameters are provided later.

[0065] In some embodiments, as shown in FIG. 3B, the I/O processing module 328 interacts with the user through the I/O devices 316 in FIG. 3A or with a user device (e.g., a user device 104 in FIG. 1) through the network communications interface 308 in FIG. 3A to obtain user input (e.g., a speech input) and to provide responses (e.g., as speech outputs) to the user input. The I/O processing module 328 optionally obtains context information associated with the user input from the user device, along with or shortly after the receipt of the user input. The context information includes user-specific data, vocabulary, and/or preferences relevant to the user input. In some embodiments, the context information also includes software and hardware states of the device (e.g., the user device 104 in FIG. 1) at the time the user request is received, and/or information related to the surrounding environment of the user at the time that the user request was received. In some embodiments, the I/O processing module 328 also sends follow-up questions to, and receives answers from, the user regarding the user request. When a user request is received by the I/O processing module 328 and the user request contains a speech input, the I/O processing module 328 forwards the speech input to the speech-to-text (STT) processing module 330 for speech-to-text conversions.

[0066] The speech-to-text processing module 330 receives speech input (e.g., a user utterance captured in a voice recording) through the I/O processing module 328. In some embodiments, the speech-to-text processing module 330 uses various acoustic and language models to recognize the speech input as a sequence of phonemes, and ultimately, a sequence of words or tokens written in one or more languages. The speech-to-text processing module 330 can be implemented using any suitable speech recognition techniques, acoustic models, and language models, such as Hidden Markov Models, Dynamic Time Warping (DTW)-based speech recognition, and other statistical and/or analytical techniques. In some embodiments, the speech-to-text processing can be performed at least partially by a third party service or on the user's device. Once the speech-to-text processing module 330 obtains the result of the speech-to-text processing, e.g., a sequence of words or tokens, it passes the result to the natural language processing module 332 for intent deduction.

[0067] The natural language processing module 332 (“natural language processor”) of the digital assistant takes the sequence of words or tokens (“token sequence”) generated by the speech-to-text processing module 330, and attempts to associate the token sequence with one or more “actionable intents” recognized by the digital assistant. An “actionable intent” represents a task that can be performed by the digital assistant, and has an associated task flow implemented in the task flow models 354. The associated task flow is a series of programmed actions and steps that the digital assistant takes in order to perform the task. The scope of a digital assistant's capabilities is dependent on the number and variety of task flows that have been implemented and stored in the task flow models 354, or in other words, on the number and variety of “actionable intents” that the digital assistant recognizes. The effectiveness of the digital assistant, however, is also dependent on the assistant's ability to infer the correct “actionable intent(s)” from the user request expressed in natural language.

[0068] In some embodiments, in addition to the sequence of words or tokens obtained from the speech-to-text processing module 330, the natural language processor 332 also receives context information associated with the user request, e.g., from the I/O processing module 328. The natural language processor 332 optionally uses the context information to clarify, supplement, and/or further define the information contained in the token sequence received from the speech-to-text processing module 330. The context information includes, for example, user preferences, hardware and/or software states of the user device, sensor information collected before, during, or shortly after the user request, prior interactions (e.g., dialogue) between the digital assistant and the user, and the like. As described in this specification, context information is dynamic, and can change with time, location, content of the dialogue, and other factors.

[0069] In some embodiments, the natural language processing is based on e.g., logy 360. The ontology 360 is a hierarchical structure containing many nodes, each node representing either an “actionable intent” or a “property” relevant to one or more of the “actionable intents” or other “properties”. As noted above, an “actionable intent” represents a task that the digital assistant is capable of performing, i.e., it is “actionable” or can be acted on. A “property” represents a parameter associated with an actionable intent or a sub-aspect of another property. A linkage between an actionable intent node and a property node in the ontology 360 defines how a parameter represented by the property node pertains to the task represented by the actionable intent node.

[0070] In some embodiments, the ontology 360 is made up of actionable intent nodes and property nodes. Within the ontology 360, each actionable intent node is linked to one or more property nodes either directly or through one or more intermediate property nodes. Similarly, each property node is linked to one or more actionable intent nodes either directly or through one or more intermediate property nodes. For example, as shown in FIG. 3C, the ontology 360 may include a “restaurant reservation” node (i.e., an actionable intent node). Property nodes “restaurant,” “date/time” (for the reservation), and “party size” are each directly linked to the actionable intent node (i.e., the “restaurant reservation” node). In addition, property nodes “cuisine,” “price range,” “phone number,” and “location” are sub-nodes of the property node “restaurant,” and are each linked to the “restaurant reservation” node (i.e., the actionable intent node) through the intermediate property node “restaurant.” For another example, as shown in FIG. 3C, the ontology 360 may also include a “set reminder” node (i.e., another actionable intent node). Property nodes “date/time” (for the setting the reminder) and “subject” (for the reminder) are each linked to the “set reminder” node. Since the property “date/time” is relevant to both the task of making a restaurant reservation and the task of setting a reminder, the property node “date/time” is linked to both the “restaurant reservation” node and the “set reminder” node in the ontology 360.

[0071] An actionable intent node, along with its linked concept nodes, may be described as a “domain.” In the present discussion, each domain is associated with a respective actionable intent, and refers to the group of nodes (and the relationships therebetween) associated with the particular actionable intent. For example, the ontology 360 shown in FIG. 3C includes an example of a restaurant reservation domain 362 and an example of a reminder domain 364 within the ontology 360. The restaurant reservation domain includes the actionable intent node “restaurant reservation,” property nodes “restaurant,” “date/time,” and “party size,” and sub-property nodes “cuisine,” “price range,” “phone number,” and “location.” The reminder domain 364 includes the actionable intent node “set reminder,” and property nodes “subject” and “date/time.” In some embodiments, the ontology 360 is made up of many domains. Each domain may share one or more property nodes with one or more other domains. For example, the “date/time” property node may be associated with many different domains (e.g., a scheduling domain, a travel reservation domain, a movie ticket domain, etc.), in addition to the restaurant reservation domain 362 and the reminder domain 364.

[0072] While FIG. 3C illustrates two example domains within the ontology 360, other domains (or actionable intents) include, for example, “initiate a phone call,” “find directions,” “schedule a meeting,” “send a message,” and “provide an answer to a question,” “read a list,” “providing navigation instructions,” “provide instructions for a task,” and so on. A “send a message” domain is associated with a “send a message” actionable intent node, and may further include property nodes such as “recipient(s),” “message type,” and “message body.” The property node “recipient” may be further defined, for example, by the sub-property nodes such as “recipient name” and “message address.”

[0073] In some embodiments, the ontology 360 includes all the domains (and hence actionable intents) that the digital assistant is capable of understanding and acting upon. In some embodiments, the ontology 360 may be modified, such as by adding or removing entire domains or nodes, or by modifying relationships between the nodes within the ontology 360.

[0074] In some embodiments, nodes associated with multiple related actionable intents may be clustered under a “super domain” in the ontology 360. For example, a “travel” super-domain may include a cluster of property nodes and actionable intent nodes related to travels. The actionable intent nodes related to travels may include “airline reservation,” “hotel reservation,” “car rental,” “get directions,” “find points of interest,” and so on. The actionable intent nodes under the same super domain (e.g., the “travels” super domain) may have many property nodes in common. For example, the actionable intent nodes for “airline reservation,” “hotel reservation,” “car rental,” “get directions,” “find points of interest” may share one or more of the property nodes “start location,” “destination,” “departure date/time,” “arrival date/time,” and “party size.”

[0075] In some embodiments, each node in the ontology 360 is associated with a set of words and/or phrases that are relevant to the property or actionable intent represented by the node. The respective set of words and/or phrases associated with each node is the so-called “vocabulary” associated with the node. The respective set of words and/or phrases associated with each node can be stored in the vocabulary index 344 in association with the property or actionable intent represented by the node. For example, returning to FIG. 3B, the vocabulary associated with the node for the property of “restaurant” may include words such as “food,” “drinks,” “cuisine,” “hungry,” “eat,” “pizza,” “fast food,” “meal,” and so on. For another example, the vocabulary associated with the node for the actionable intent of “initiate a phone call” may include words and phrases such as “call,” “phone,” “dial,” “ring,” “call this number,” “make a call to,” and so on. The vocabulary index 344 optionally includes words and phrases in different languages.

[0076] The natural language processor 332 receives the token sequence (e.g., a text string) from the speech-to-text processing module 330, and determines what nodes are implicated by the words in the token sequence. In some embodiments, if a word or phrase in the token sequence is found to be associated with one or more nodes in the ontology 360 (via the vocabulary index 344), the word or phrase will “trigger” or “activate” those nodes. Based on the quantity and/or relative importance of the activated nodes, the natural language processor 332 will select one of the actionable intents as the task that the user intended the digital assistant to perform. In some embodiments, the domain that has the most “triggered” nodes is selected. In some embodiments, the domain having the highest confidence value (e.g., based on the relative importance of its various triggered nodes) is selected. In some embodiments, the domain is selected based on a combination of the number and the importance of the triggered nodes. In some embodiments, additional factors are considered in selecting the node as well, such as whether the digital assistant has previously correctly interpreted a similar request from a user.

[0077] In some embodiments, the digital assistant also stores names of specific entities in the vocabulary index 344, so that when one of these names is detected in the user request, the natural language processor 332 will be able to recognize that the name refers to a specific instance of a property or sub-property in the ontology. In some embodiments, the names of specific entities are names of businesses, restaurants, people, movies, and the like. In some embodiments, the digital assistant searches and identifies specific entity names from other data sources, such as the user's address book, a movies database, a musicians database, and/or a restaurant database. In some embodiments, when the natural language processor 332 identifies that a word in the token sequence is a name of a specific entity (such as a name in the user's address book), that word is given additional significance in selecting the actionable intent within the ontology for the user request.

[0078] For example, when the words “Mr. Santo” are recognized from the user request, and the last name “Santo” is found in the vocabulary index 344 as one of the contacts in the user's contact list, then it is likely that the user request corresponds to a “send a message” or “initiate a phone call” domain. For another example, when the words “ABC Café” are found in the user request, and the term “ABC Café” is found in the vocabulary index 344 as the name of a particular restaurant in the user's city, then it is likely that the user request corresponds to a “restaurant reservation” domain.

[0079] User data 348 includes user-specific information, such as user-specific vocabulary, user preferences, user address, user's default and secondary languages, user's contact list, and other short-term or long-term information for each user. In some embodiments, the natural language processor 332 uses the user-specific information to supplement the information contained in the user input to further define the user intent. For example, for a user request “invite my friends to my birthday party,” the natural language processor 332 is able to access user data 348 to determine who the “friends” are and when and where the “birthday party” would be held, rather than requiring the user to provide such information explicitly in his/her request.

[0080] Other details of searching an ontology based on a token string is described in U.S. Utility application Ser. No. 12/341,743 for “Method and Apparatus for Searching Using an Active Ontology,” filed Dec. 22, 2008, the entire disclosure of which is incorporated herein by reference.

[0081] In some embodiments, once the natural language processor 332 identifies an actionable intent (or domain) based on the user request, the natural language processor 332 generates a structured query to represent the identified actionable intent. In some embodiments, the structured query includes parameters for one or more nodes within the domain for the actionable intent, and at least some of the parameters arc populated with the specific information and requirements specified in the user request. For example, the user may say “Make me a dinner reservation at a sushi place at 7.” In this case, the natural language processor 332 may be able to correctly identify the actionable intent to be “restaurant reservation” based on the user input. According to the ontology, a structured query for a “restaurant reservation” domain may include parameters such as {Cuisine}, {Time}, {Date}, {Party Size}, and the like. In some embodiments, based on the information contained in the user's utterance, the natural language processor 332 generates a partial structured query for the restaurant reservation domain, where the partial structured query includes the parameters {Cuisine=“Sushi”} and (Time=“7 pm”). However, in this example, the user's utterance contains insufficient information to complete the structured query associated with the domain. Therefore, other necessary parameters such as {Party Size} and {Date} are not specified in the structured query based on the information currently available. In some embodiments, the natural language processor 332 populates some parameters of the structured query with received context information. For example, in some embodiments, if the user requested a sushi restaurant “near me,” the natural language processor 332 populates a {location} parameter in the structured query with GPS coordinates from the user device 104.

[0082] In some embodiments, the natural language processor 332 passes the structured query (including any completed parameters) to the task flow processing module 336 (“task flow processor”). The task flow processor 336 is configured to receive the structured query from the natural language processor 332, complete the structured query, if necessary, and perform the actions required to “complete” the user's ultimate request. In some embodiments, the various procedures necessary to complete these tasks are provided in task flow models 354. In some embodiments, the task flow models include procedures for obtaining additional information from the user, and task flows for performing actions associated with the actionable intent.

[0083] As described above, in order to complete a structured query, the task flow processor 336 may need to initiate additional dialogue with the user in order to obtain additional information, and/or disambiguate potentially ambiguous utterances. When such interactions are necessary, the task flow processor 336 invokes the dialogue processing module 334 (“dialogue processor 334”) to engage in a dialogue with the user. In some embodiments, the dialogue processor 334 determines how (and/or when) to ask the user for the additional information, and receives and processes the user responses. The questions are provided to and answers are received from the users through the I/O processing module 328. In some embodiments, the dialogue processor 334 presents dialogue output to the user via audio and/or visual output, and receives input from the user via spoken or physical (e.g., clicking) responses. Continuing with the example above, when the task flow processor 336 invokes the dialogue flow processor 334 to determine the “party size” and “date” information for the structured query associated with the domain “restaurant reservation,” the dialogue flow processor 335 generates questions such as “For how many people?” and “On which day?” to pass to the user. Once answers are received from the user, the dialogue flow processor 334 can then populate the structured query with the missing information, or pass the information to the task flow processor 336 to complete the missing information from the structured query.

[0084] In some cases, the task flow processor 336 may receive a structured query that has one or more ambiguous properties. For example, a structured query for the “send a message” domain may indicate that the intended recipient is “Bob,” and the user may have multiple contacts named “Bob.” The task flow processor 336 will request that the dialogue processor 334 disambiguate this property of the structured query. In turn, the dialogue processor 334 may ask the user “Which Bob?”, and display (or read) a list of contacts named “Bob” from which the user may choose.

[0085] Once the task flow processor 336 has completed the structured query for an actionable intent, the task flow processor 336 proceeds to perform the ultimate task associated with the actionable intent. Accordingly, the task flow processor 336 executes the steps and instructions in the task flow model according to the specific parameters contained in the structured query. For example, the task flow model for the actionable intent of “restaurant reservation” may include steps and instructions for contacting a restaurant and actually requesting a reservation for a particular party size at a particular time. For example, using a structured query such as: {restaurant reservation, restaurant=ABC Café, date=3/12/2012, time=7 pm, party size=5}, the task flow processor 336 may perform the steps of: (1) logging onto a server of the ABC Cafe or a restaurant reservation system such as OPENTABLE®, (2) entering the date, time, and party size information in a form on the website, (3) submitting the form, and (4) making a calendar entry for the reservation in the user's calendar.

[0086] In some embodiments, the task flow processor 336 employs the assistance of a service processing module 338 (“service processor”) to complete a task requested in the user input or to provide an informational answer requested in the user input. For example, the service processor 338 can act on behalf of the task flow processor 336 to make a phone call, set a calendar entry, invoke a map search, invoke or interact with other user applications installed on the user device, and invoke or interact with third party services (e.g., a restaurant reservation portal, a social networking website, a banking portal, etc.). In some embodiments, the protocols and application programming interfaces (API) required by each service can be specified by a respective service model among the services models 356. The service processor 338 accesses the appropriate service model for a service and generates requests for the service in accordance with the protocols and APIs required by the service according to the service model.

[0087] For example, if a restaurant has enabled an online reservation service, the restaurant can submit a service model specifying the necessary parameters for making a reservation and the APIs for communicating the values of the necessary parameter to the online reservation service. When requested by the task flow processor 336, the service processor 338 can establish a network connection with the online reservation service using the web address stored in the service model, and send the necessary parameters of the reservation (e.g., time, date, party size) to the online reservation interface in a format according to the API of the online reservation service.

[0088] In some embodiments, the natural language processor 332, dialogue processor 334, and task flow processor 336 are used collectively and iteratively to infer and define the user's intent, obtain information to further clarify and refine the user intent, and finally generate a response (i.e., an output to the user, or the completion of a task) to fulfill the user's intent.

[0089] In some embodiments, after all of the tasks needed to fulfill the user's request have been performed, the digital assistant 326 formulates a confirmation response, and sends the response back to the user through the I/O processing module 328. If the user request seeks an informational answer, the confirmation response presents the requested information to the user. In some embodiments, the digital assistant also requests the user to indicate whether the user is satisfied with the response produced by the digital assistant 326.

[0090] More details on the digital assistant can be found in the U.S. Utility application Ser. No. 12/987,982, entitled “Intelligent Automated Assistant”, filed Jan. 18, 2010, U.S. Utility Application No. 61/493,201, entitled “Generating and Processing Data Items That Represent Tasks to Perform”, filed Jun. 3, 2011, the entire disclosures of which are incorporated herein by reference.

[0091] In most scenarios, when the digital assistant receives a user input from a user, the digital assistant attempts to provide an appropriate response to the user input with as little delay as possible. For example, suppose the user requests certain information (e.g., current traffic information) by providing a speech input (e.g., “How does the traffic look right now?”). Right after the digital assistant receives and processes the speech input, the digital assistant optionally provides a speech output (e.g., “Looking up traffic information . . . ”) acknowledging receipt of the user request. After the digital assistant obtains the requested information in response to the user request, the digital assistant proceeds to provide the requested information to the user without further delay. For example, in response to the user's traffic information request, the digital assistant may provide a series of one or more discrete speech outputs separated by brief pauses (e.g., “There are 2 accidents on the road. <Pause> One accident is on 101 north bound near Whipple Avenue. <Pause> And a second accident is on 85 north near 280.”), immediately after the speech outputs are generated.

[0092] For the purpose of this specification, the initial acknowledgement of the user request and the series of one or more discrete speech outputs provided in response to the user request are all considered sub-responses of a complete response to the user request. In other words, the digital assistant initiates an information provision process for the user request upon receipt of the user request, and during the information provision process, the digital assistant prepares and provides each sub-response of the complete response to the user request without requiring further prompts from the user.

[0093] Sometimes, additional information or clarification (e.g., route information) is required before the requested information can be obtained. In such scenarios, the digital assistant outputs a question (e.g., “Where are you going?”) to the user asking for the additional information or clarification. In some embodiments, the question provided by the digital assistant is considered a complete response to the user request because the digital assistant will not take further actions or provide any additional response to the user request until a new input is received from the user. In some embodiments, once the user provides the additional information or clarification, the digital assistant initiates a new information provision process for a “new” user request established based on the original user request and the additional user input.

[0094] In some embodiments, the digital assistant initiates a new information provision process upon receipt of each new user input, and each existing information provision process terminates either (1) when all of the sub-responses of a complete response to the user request have been provided to the user or (2) when the digital assistant provides a request for additional information or clarification to the user regarding a previous user request that started the existing information provision process.

[0095] In general, after a user request for information or performance of a task is received by the digital assistant, it is desirable that the digital assistant provides a response (e.g., either an output containing the requested information, an acknowledgement of a requested task, or an output to request a clarification) as promptly as possible. Real-time responsiveness of the digital assistant is one of the key factors in evaluating performance of the digital assistant. In such cases, a response is prepared as quickly as possible, and a default delivery time for the response is a time immediately after the response is prepared.

[0096] Sometimes, however, after an initial sub-response provided immediately after receipt of the user input, the digital assistant provides the remaining one or more sub-responses one at a time over an extended period of time. In some embodiments, the information provision process for a user request is stretched out over an extended period of time that is longer than the sum of the time required to provide each sub-response individually. For example, in some embodiments, short pauses (i.e., brief periods of silence) are inserted between an adjacent pair of sub-responses (e.g., a pair of consecutive speech outputs) when they are delivered to the user through an audio-output channel.

[0097] In some embodiments, a sub-response is held in abeyance after it is prepared and is delivered only when a predetermined condition has been met. In some embodiments, the predetermined condition is met when a predetermined trigger time has been reached according to a system clock and/or when a predetermined trigger event has occurred. For example, if the user says to the digital assistant “set me a timer for 5 minutes,” the digital assistant initiates an information provision process upon receipt of the user request. During the information provision process, the digital assistant provides a first sub-response (e.g., “OK, timer started.”) right away, and does not provide a second and final sub-response (e.g., “OK, five minutes are up”) until 5 minutes later. In such cases, the default delivery time for the first sub-response is a time immediately after the first sub-response is prepared, and the default delivery time for the second, final sub-response is a time immediately after the occurrence of the trigger event (e.g., the elapse of 5 minutes from the start of the timer). The information provision process is terminated when the digital assistant finishes providing the final sub-response to the user. In various embodiments, the second sub-response is prepared any time (e.g., right after the first sub-response is prepared, or until shortly before the default delivery time for the second sub-response) before the default delivery time for the second sub-response.

[0098] As will be described in more details later in this specification, a context sensitive interruption handler (e.g., the interruption handling module 340 in FIG. 3A) is implemented on top of the default rules for providing responses to the user requests and/or for providing the alert items for reminders and notifications. In some embodiments, the interruption handler gathers information regarding the present context in real-time, and determines in real-time whether the default rules for provision of responses, reminders and/or notifications need to be altered because the device is currently receiving speech input for a user. For example, in some contexts, it would be more suitable to delay (e.g., staying, at least temporary) provision of a non-urgent speech output because a user is speaking into the device, while other times it may be more suitable to provide an urgent speech output immediately (e.g., “barge-in,” or interrupt the user). In addition, in some contexts, it is acceptable and in fact, more suitable to forgo providing the speech output altogether.

[0099] FIGS. 4A-4C illustrate exemplary scenarios in which a digital assistant provides a speech output, or does not provide a speech output, in accordance with some embodiments. In FIGS. 4A-4C, solid boxes corresponding to speech outputs (e.g., SO1 in FIG. 4A) indicate speech outputs that are actually provided by the device. Dashed boxes, on the other hand (e.g., SO2 in FIG. 4A), indicate speech outputs that are not actually provided by the device at the corresponding time and location, but otherwise would be provided by the device if not for the detection of speech input by the user, as explained in greater detail with reference to the individual figures.

[0100] FIG. 4A illustrates an exemplary scenario in which a speech output is permanently forgone by the device. At the outset, the user is heading East (401) on East Alder Ave. At a first location designated by 402-1, the user requests that the device provide turn-by-turn directions to a library by stating, “Take me to the library” as a speech input SI1. The location at which the user finishes the speaking is designated by 402-2, which is distinct from 402-1 by virtue of the fact that the user is speaking while moving. Thus, the bars corresponding to respective speech inputs and outputs (e.g., the bar between 402-1 and 402-2 corresponding to SI1) indicate a distance or, equivalently, a length of time that the respective input/output requires to recite (e.g., speak).

[0101] The device receives the speech input and performs the necessary operations to, for example, determine the location of the nearest library, as described in greater detail with reference to method 500 and FIGS. 5A-5D. In this example, the device determines that library 404 is the nearest library and responds promptly with a speech output SO1 (“Ok, Continue Straight”)

[0102] At a location designated by 405-1, a phone feature included on the same device as the digital assistant receives an incoming call, as indicated by ring-tone icon 406. The user answers the phone by providing speech input SI2, stating, “Hey John! Haven't heard from you in ages. How is the family?” At the completion of speech input SI2, the user is at a location designated by 405-2. However, in the interim between 405-1 and 405-2, the device receives (e.g., from a server or a different module on the same device) a speech output SO2 indicating, “Turn right on First Street in 3 miles.” In this example, speech output SO2 has a low measure of urgency, because the device is scheduled to warn the user of the upcoming turn one or more additional times before the user reaches First Street (e.g., additional warning such as, “Turn Right in 1 mile,” and/or, “Turn right now onto First Street”). Because the device was receiving speech input SI2 when speech output SO2 was to be outputted (407-1 until 407-2), the device stays output of speech output SO2. Furthermore, because of the very low priority associated with speech output SO2 (e.g., due to the redundancy associated with the turn-by-turn direction in this example), the stay actually forgoes output of speech output SO2 altogether (e.g., never outputs a command to turn left in three miles, relying instead on the 1 mile and immediate warnings).

[0103] FIG. 4B illustrates an exemplary scenario in which a speech output is immediately provided to a user, in accordance with some embodiments. Like reference numerals shared between FIGS. 4A and 4B refer to analogous aspects of the respective scenarios. Thus, for brevity, those analogous aspects are not repeated here.

[0104] FIG. 4B differs from FIG. 4A in that the phone receives an incoming call, as indicated by the ring-tone icon 406, at a much closer proximity to First Street than in FIG. 4A. While the user is answering the phone via speech input SI2, the device receives a speech output SO3 corresponding to a turn-by-turn direction command indicating that the user should turn right very soon (e.g., in this example, 100 feet). Because of the urgency of the message, the device “barges-in” (e.g., interrupts the user while the user is speaking) to output, “Turn right in 100 feet.”

[0105] FIG. 4C illustrates an exemplary scenario in which a speech output is temporarily stayed, and then later provided to a user, in accordance with some embodiments. Like reference numerals shared between FIGS. 4A and 4C refer to analogous aspects of the respective scenarios. Thus, for brevity, those analogous aspects are not repeated here.

[0106] During a speech input SI3, the user requests that the device inform the user of the Knicks' score whenever the game should end, stating, “Tell me the Knicks' score when the game ends.” The device responds promptly acknowledging the request, stating, “Ok, I will tell you the score of the Knicks' game when it ends.” As explained previously, the phone receives an incoming call, which the user answers in speech input SI2 by stating, “Hey John! Haven't heard from you in ages. How is the family?” During SI2, the Knicks' game ends the device receives a speech output SO5 indicating the score, as requested, to be provided to the user. In this example, speech output SO5 is not considered urgent because the Knicks' score will not change in the time that the user is speaking (e.g., during the time that the device is receiving speech input) For this reason, the device stays speech output SO5, as indicated by arrow 408, until the user has finished speaking, and then outputs speech output SO5. However, in some embodiments, the device response to the user request in a non-audible fashion, such as by displaying the Knicks' score on a display of the device. In some embodiments, because a displayed response will not interrupt the user's speech, such a response is provided without delay. In some embodiments, such a displayed response is provided in conjunction with, or alternatively, in lieu of, a stayed speech output (e.g., when the displayed response is in lieu of a speech output, the speech output is forgone altogether).

[0107] FIGS. 5A-5D are flow diagrams of an exemplary method 500 implemented by a digital assistant for determining whether or not to provide a speech output to a user based on a determination or whether or not the device is currently receiving speech input from a user, as well as the urgency of the speech output. In some embodiments, the determination of whether or not to provide the speech output is performed dynamically by an interruption handler (e.g., the interruption handler 340 in FIG. 3A) of the digital assistant in real-time based on the present-context.

[0108] In some embodiments, prior to receiving the speech output (cf. 506), the device receives (502) a request from the user to perform a digital assistant task. For example, the user requests that the digital assistant find a cheap nearby restaurant by stating as a speech input, for example, “Find me something for dinner, not too expensive.” Alternatively, the user requests that the digital assistant make a reservation at a particular restaurant, for example, by stating as a speech input, “Make me a reservation at Boulevard for four,” Alternatively, the user asks for turn-by-turn directions to a local landmark (“Directions to the Golden Gate Bridge”), or ask for a baseball score (“How did the Sox do?”), or a stock price (“How did Apple's stock do today?”).

[0109] In some embodiments, prior to receiving a speech output (cf. 506), the device sends (504) the request to a digital assistant server. The speech output is received from the server in response to the request. In some embodiments, prior to sending the request to the server, the device performs a speech-to-text operation (e.g., with STT Processing Module 330). In some embodiments, speech-to-text is performed at the server. In some embodiments, the device performs the natural language processing (e.g., with Natural Language Processing Module 322) including performing the ontology, vocabulary analysis and context matching using user data (for example, to disambiguate which “Sox” team the user is interested in, based on preferences such as favorites, browser history and/or digital assistant request history). The server then performs any remaining operations necessary to service the request (e.g., identifies one or more actionable items, one or more missing properties from the actionable properties, searches one or more database and/or the Internet for missing information, etc.) In some embodiments, the server prepares a response (e.g., a text string) and returns the response to the user. In some embodiments, the server prepares a speech response (e.g., audio data) and transmits the speech response to the digital assistant.

[0110] In any event, the device receives (506) a speech output to be provided to a user of the device. In some embodiments, the speech output is received from the server in response to the request (e.g., the speech output is an appropriate response to the request made by the user, be it a request for a dinner reservation or turn-by-turn directions). In some embodiments, receiving the speech output includes (508) generating the speech output at the device (e.g., for example, the server returns a text string in response to the request and the device generates the speech output from the text string using a text-to-speech engine). It should be understood that, in some embodiments, receiving a speech output means receiving from a server (which optionally includes additional processing operations such as text-to-speech operations). Alternatively, or in addition, receiving a speech output means receiving at a first device component (e.g., a module such as interruption handling module 340 or a processor 304 executing instructions held in a module such as interruption handling module 340) from a second device component (e.g., a module such as natural language processing module 332 or a processor 304 executing instructions held in a module such as natural language processing module 332).

[0111] The device determines (510) if the device is currently receiving speech input from a user. For example, in some embodiments, the device is (512) a telephone, and determining if the device is currently receiving speech input from the user includes determining if the user is participating in a telephone conversation with a remote user. In such embodiments, the device determines that it is currently receiving speech input from the user if the user is currently speaking in the conversation. In some embodiments, when a party on the other end of the telephone conversation is speaking, or if there is silence while the user and the other party go about doing other things, the device determines that it is not currently receiving speech input (e.g., in some implementations, an active telephone conversation is sufficient for a determination that the device is receiving speech input, while in alternative implementations, the device determines that speech input is being received when the user is actually the one speaking in the conversation).

[0112] In some embodiments, determining if the device is currently receiving speech input from the user includes (514) determining if a last speech input was received within a predetermined period of time. For example, because there are natural pauses in the ebb-and-flow of conversation (e.g., pauses to catch one's breath, pauses to consider what to say next), in some embodiments, the devices waits a predetermined amount of time before concluding that the user is not speaking, rather than detecting speech input in an instantaneous or nearly instantaneous fashion. In some embodiments, the predetermined period of time is (516) a function of a measure of a urgency of the output. For example, when the device has an urgent message (“Turn right NOW!”) in an output queue, the device will wait a shorter amount of time before determining that the user is not speaking, thus barging-in the moment the user pauses to catch his or her breath or consider what to say next). In some embodiments, determining if the device is currently receiving speech input includes a squelch determination (e.g., based on a particular strength or directionality threshold at a device microphone) to disambiguate, for example, background noise and/or speech made by the user but not intended as speech input (e.g., during a telephone conversation, when the user pauses the conversation to talk to another party in-person).

[0113] Upon determining that the device is not currently receiving speech input from the user, the device provides (518) the speech output to the user. In some embodiments, the device provides (520) audio data received from the remote user (cf. 512, when the user is participating in a telephone) and the speech output to the user contemporaneously without staying provision of the speech output due to the received audio data. For example, in such embodiments, when the remote user (i.e., the other party) is talking during a telephone conversation, the device will nevertheless provide speech output from the digital assistant. In some embodiments, providing audio data (e.g., speech) received from the remote user and the speech output to the user contemporaneously means muting the audio data from the remote user temporarily while the speech output is provided. For example, in such embodiments, when the remote user says, “Four score and seven years ago our fathers brought forth on this continent a new nation, conceived in liberty, and dedicated to the proposition that all men are created equal” and the speech output in an output queue is, “Turn left,” the audio actually provided to the user will be, “Four score and seven years ago our fathers brought forth on this continent a . . . ‘Turn Left’ . . . , conceived in liberty, and dedicated to the proposition that all men are created equal.” The user will thus be aware that the remote user is reciting Lincoln's Gettysburg address, and will also understand the instructions to turn left. In some embodiments, the audio data received from the remote user and the speech output are provided using different vocal accents and/or volumes to disambiguate the remote user from the digital assistant.

[0114] In some circumstances, the user will have configured the device to override provision of the speech output. For example, when the device is in a do-not-disturb mode of operation, provision of the speech output is forgone (522). In some embodiments, the device is in a do-not-disturb mode of operation when the user has configured the device to be in a do-not-disturb mode of operation. In some embodiments, the device is in a do-not-disturb mode of operation when the user has configured a device to operation in a mode distinct from do-not-disturb, but nevertheless includes do-not-disturb as a feature (e.g., the device is in an airplane mode, or a quiet mode, or the user has configured the device to be in a quiet mode during particular hours of the day, etc.

[0115] In some embodiments, during provision (524) of the speech output, the device receives (526) speech input from the user. For example, the device is in the midst of providing a speech output when the user interrupts by talking as part of a telephone conversation or speaking another request for a digital assistant operation. As an example of the latter scenario, when a user has previously requested that the device locate a nearby Chinese restaurant, the user may interrupt the response to indicate that he or she also needs to send an SMS message to a coworker. In such embodiments, the device will discontinue (528) speech output. In such embodiments, the device will determine (530) if completion criteria corresponding to the speech output have been met. In some embodiments, the completion criteria are met (532) when a predefined percentage of the speech output has already been provided to the user. For example, in some embodiments, the predefined percentage of speech output is (534) a percentage from the group consisting of: 50%, 60%, 70%, and 80%. Upon determining that the completion criteria have not been met, the device stays (536) at least part of the speech output for later time, and upon determining that the completion criteria have been met, the device forgoes output of the remainder of the speech output altogether. In some embodiments, the completion criteria are met when the device determines that the remainder of the message is moot (e.g., after requesting Chinese food, and during a recitation by the device of a list of local Chinese restaurants, the user declares, “Never mind, I want That food.”)

[0116] Upon determining that the device is receiving speech input from the user, the device determines (538) if provision of the speech output is urgent. In some embodiments, the speech output is urgent (540) when the speech output meets user-configurable criteria for immediate provision. For example, in some embodiments, the user-configurable criteria are met (542) when the device receives an electronic message from a person that the user has previously identified as a very important person (VIP). Alternatively or in addition, in some embodiments, the user-configurable criteria are met (544) when the device receives a stock price update and the user has previously configured the device to provide the stock price update immediately (for example, the user has configured the device to alert him or her when a particular stock price exceeds a particular value, so that the user can consider selling the stock as fast as possible). In some embodiments, a determination is made as to whether or not provision of the speech input is urgent based on context. For example, when the speech output includes directions to turn in the near future (“Turn left NOW!”) the device recognizes that the message is urgent. Upon determining that provision of the speech output is urgent, the device provides (546) the speech output to the user (e.g., the device “barges-in” and provides the speech output despite receiving speech input from the user). In some embodiments, the device provides (548) the speech output to the user without delay (e.g., additional delay added on account of the fact that the user is speaking, on top of any required processing time needed to produce the output).

[0117] Upon determining that provision of the speech output is not urgent, the device stays (550) provision of the speech output to the user. As explained in greater detail below, in some circumstances staying provision of the speech output means delaying provision of the speech output until a later time, and then providing the speech output, while in other circumstances staying means forgoing provision of the speech output altogether and never providing that particular speech output. In some circumstances, whether staying means temporarily delaying provision of the speech output or permanently forgoing provision of the speech output depends on the particular embodiment, implementation and the context surrounding the speech output (cf. 562). In some embodiments, when the device is in a special mode of operation, the device provides (552) the speech output without delay (e.g., even if the device is currently receiving speech input from the user). For example, in some embodiments the device includes an “Interrupt Me” mode of operation whereby the user is to be interrupted by the digital assistant (e.g., the digital assistant is to barge-in) regardless of whether the device is receiving speech input. In some embodiments, the special mode of operation is (553) one or more of the group consisting of a hold mode of operation and a mute mode of operation.

[0118] Flow paths 553-1, 553-2, and 553-3 represent additional operation that are optionally performed upon determining that provision of the speech output is not urgent, in accordance with some embodiments of method 500. It should be understood that the various operations described with respect to flow paths 553 are not necessarily mutually exclusive and, in some circumstances, combined.

[0119] For example, according to some embodiments, upon determining that the device is no longer receiving speech input from the user, the device provides (554) the speech output to the user. In some embodiments, determining that the device is no longer receiving speech input from the user includes (556) determining that a predefined amount of time has elapsed between a time of a last speech input and a current time. In some embodiments, the predefined amount of time is a function of a measure of the urgency of the speech output. In some embodiments, the predetermined amount of time is (560) a monotonically decreasing function of the measure of the urgency of the speech output, thereby providing speech outputs with a greater measure of urgency in a lesser amount of time. For example, in these embodiments, the device waits a shorter amount of time before providing an urgent speech output after the user has finished speaking than if the speech output was less urgent.

[0120] In some embodiments, the device determines (562) if the output meets message skipping criteria. In some embodiments, the message skipping criteria are met (564) when the measure of the urgency is lower than a predefined threshold. For example, when the speech output is one of several warnings in a sequence of warnings, in some circumstances it is unnecessary to provide the user with each warning in the sequence of warnings. In some embodiments, the message skipping criteria are met (566) when the speech output is a navigational command in a set of turn-by-turn directions and the device is scheduled to give a corresponding navigational command at a later time. For example, the device is scheduled to provide navigation commands at 2 miles, 1 miles, ½ a mile and moments before a turn. In such circumstances, when the user is providing speech input when the 1 mile command would otherwise be recited, the device forgoes provision of the 1 mile command altogether. The driver will correspondingly still be notified of the turn by the ½ mile command as well as moments before the turn.

[0121] In some embodiments, when the device includes a display, upon determining that provision of the speech output is not urgent, the device provides (568) a displayed output corresponding to the speech output.

[0122] The operations described above with reference to FIGS. 5A-5D are, optionally, implemented by components depicted in FIG. 2 and/or FIG. 3. For example, receiving operation 504, providing operation 520, receiving operation 526 are, optionally, implemented by digital assistant 326, I/O processing module 328, interruption handling module 340, and/or natural language processing module 332, which are described in detail above. Similarly, it would be clear to a person having ordinary skill in the art how other processes can be implemented based on the components depicted in FIG. 2 and/or FIG. 3.

[0123] It should be understood that the particular order in which the operations have been described above is merely exemplary and is not intended to indicate that the described order is the only order in which the operations could be performed. One of ordinary skill in the art would recognize various ways to reorder the operations described herein.

[0124] The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.