Acoustic coupling device

[0002] This application claims benefit under 35 U.S.C. 119 (e) of U.S. Provisional Application No. 60/182,279, filed Feb. 14, 2000.

[0003] The present invention relates generally to the field of audiometric devices and associated screening methods. More particularly, the invention relates to an acoustic coupling device for use in connection with equipment for stimulating the reaction to sound in a subject.

[0004] Language acquisition in infants requires a critical period of hearing capacity, which spans the frequency range of human speech. The critical period extends from birth to about two to three years of age, when infants typically begin to talk with some level of proficiency.

[0005] Various hearing screening techniques have been developed over the years which present a sound input into the ear of a subject (i.e., infant) and detect a response to that input. The response is related to the characteristics of the sound input and the conditions inside the ear, the neural connections, and the vibration transmission mechanism of the ear.

[0006] In many instances, hearing screening is performed by using an earphone having a cavity that fits closely about the ear. Auditory tones or “clicks” are fed into the earphone cavity, and the response generated by the patient's ear and the neural conduction system in response to the auditory tones is sensed by a transducer. The transducer may be, for example, a microphone, suitable electrodes, piezo electric materials and like devices that generate signals representative of the response to the auditory input.

[0007] There are, however, several problems associated with the noted technique. A major problem is that ambient noises, internal or external to the cavity, are capable of interfering with the stimulus or the response signals and, hence, the results. In most cases, the monitoring equipment has mechanisms, such as microphones, for detecting and compensating for ambient background noise. Illustrative is the disposable earphone disclosed in U.S. Pat. No. 4,930,520 (Liverani), which is sold under the trademark Ear Couplers® by Natus Medical, Inc.

[0008] The Liverani earphone includes a toroidal baffle of anechoic, insulative foam, a clear planar window plastic sheet adhered to one side of the baffle defining a cavity, and an adhesive coating on the other side of the baffle for bonding the disposable earphone to the region surrounding the infant's ear. The earphone is employed with transducers for transferring acoustical energy through a pneumatic tube to the infant's ear for testing.

[0009] One of the problems with the Liverani device is that the earphone is somewhat cost-ineffective in that the entire earphone is not re-usable and must be disposed of after each use. Another problem with the device is that its construction is not capable of adjustment for infants with different size ears. As a result, it is necessary to manufacture different size earphones and maintain an inventory of the different sizes to obtain acceptable test performance for infants having different sized ears.

[0010] A further problem is that the Liverani device does not include any means for regulating or monitoring the amplitude of the stimulus presented to the infant.

[0011] In U.S. Pat. No. 5,913,309 a disposable earphone element is disclosed for use in hearing screening tests, which addresses some of the disadvantages associated with the Liverani device. The disposable element similarly includes an adhesive on one side of the element, which is adapted to adhere to the patient's skin around the ear. An adhesive is further provided on the opposite side of the element to temporarily adhere to the earphone. Thus, after a test is conducted, the disposable element is merely removed and replaced, allowing one to reuse the earphone.

[0012] Although the disposable element disclosed in the '309 eliminates the need to replace the entire earphone after each use, replacement of the disposable element is still somewhat cost-ineffective. Further, the disposable element does not include any means for regulating or monitoring the amplitude of the stimulus.

[0013] Finally, a problem associated with each of the noted devices is that the adhesive employed to adhere the devices to the skin is generally ineffective to maintain full contact with the infant during the period of hearing screening. Thus, ambient noise can, and in many instances will, enter into the cavity.

[0014] Accordingly, there remains a need for an improved acoustic coupling device that overcomes the problems of prior art devices and, further, provides means for regulating and/or monitoring the amplitude of the stimulus presented to the subject.

[0015] In accordance with the above objects and those that will be mentioned and will become apparent below, the acoustic coupling device (or apparatus) in accordance with this invention comprises engagement means adapted to engage a hearing screening device, the engagement means being adapted to receive an acoustic stimulus from the hearing screening device and transmit at least one response signal from a subject (or patient) to the hearing screening device, stimulus monitoring means in communication with the engagement means for monitoring the acoustic stimulus, at least a first earpiece disposed proximate the cavity of at least one of said subject's ears having a stimulus input in communication with the engagement means adapted to receive the acoustic stimulus, the stimulus input being further adapted to receive and transmit the response signal from the subject to the engagement means, the earpiece further including a response signal output adapted to receive and transmit the response signal, and response signal monitoring means in communication with the response signal output for monitoring the response signal.

[0016] In an additional embodiment of the invention the acoustic coupling device comprises engagement means adapted to engage said hearing screening device, the engagement means being adapted to receive a first acoustic stimulus from the hearing screening device and transmit at least one response signal from the subject to said hearing screening device, stimulus monitoring means in communication with the engagement means for monitoring the first acoustic stimulus, stimulus regulator means in communication with the stimulus monitoring means for providing a second acoustic stimulus in response to the first acoustic stimulus, at least a first earpiece disposed proximate the cavity of at least one of said subject's ears having a stimulus input in communication with the engagement means and the stimulus regulator means adapted to receive the second acoustic stimulus, the stimulus input being further adapted to receive and transmit the response signal to the engagement means, the earpiece further including a response signal output adapted to receive the response signal, and response signal monitoring means in communication with the response signal output for monitoring the response signal.

[0017] Further features and advantages will become apparent from the following and more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings, and in which like referenced characters generally refer to the same parts or elements throughout the views, and in which:

[0018] FIG. 1 is an illustration of a prior art hearing screening test device;

[0019] FIG. 2 is an illustration of the hearing screening device shown in FIG. 1 incorporating the acoustic coupling apparatus according to the invention;

[0020] FIG. 3A is a schematic illustration of one embodiment of the acoustic coupling apparatus according to the invention;

[0021] FIG. 3B is a schematic illustration of the acoustic coupling apparatus showing the engagement of the acoustic coupling apparatus to the hearing screening device according to the invention;

[0022] FIG. 4 is a schematic illustration of a further embodiment of the acoustic coupling apparatus according to the invention;

[0023] FIG. 5 is a sectional view of an earpiece according to the invention;

[0024] FIG. 6A is a perspective view of the earpiece shown in FIG. 5; and

[0025] FIG. 6B is a perspective view of an additional embodiment of the earpiece according to the invention.

[0026] The present invention substantially reduces or eliminates the disadvantages and drawbacks of prior art audiometric screening devices and systems. As discussed in detail below, in one embodiment of the invention the acoustic coupling device includes a plurality of multi-shaped, disposable ear pieces adapted to sealably engage a subject's ear canal (or cavity), monitoring means adapted to monitor at least the amplitude of the stimulus presented to the subject and the response signal emanating from the subject's ear(s), and engagement means adapted to facilitate the use of the invention on conventional hearing screening test devices. In an additional embodiment of the invention, the acoustic coupling device also includes regulator means adapted to control the stimulus presented to the subject.

[0027] Referring first to FIG. 1, there is shown a prior art audiometric screening device (or system) 20. The device 20 includes a laptop computer 22 having a monitor 23 for displaying one or more characteristics of the processed signals emanating from the subject 10. The device 20 also includes means for providing at least one acoustic stimulus signal and means for receiving response signals from the subject 10.

[0028] The audiometric screening system 20 further includes a probe 24 having a pair of earphone assemblies 26, such as that disclosed in U.S. Pat. No. 5,826,582, for presenting the acoustic stimulus signal(s) to the subject 10. The earphone assemblies 26 are also adapted to receive the evoked otoacoustic emission (OAE) response signal from the subject's ear.

[0029] As discussed above, two major drawbacks of the noted device are (i) the earphone assemblies 26 must be replaced after each test and (ii) the earphone assemblies 26 do not include any means for monitoring or regulating the stimulus and, in particular, the amplitude of the stimulus presented to the subject 10.

[0030] Referring now to FIG. 2, there is shown one embodiment of the acoustic coupling device 32 of the invention incorporated into the device shown in FIG. 1. As illustrated in FIG. 2, the audiometric coupling device 32 is adapted to engage and, hence, communicate with the conventional audiometric device 20 via probe 24 (see also FIG. 3B).

[0031] Referring now to FIG. 3A, there is shown a block diagram of a first embodiment of the acoustic coupling device 32. The coupling device 32 includes first and second inputs 40a, 40bhaving a lumen 40ctherein adapted to receive and transmit the stimulus signal provided by the hearing screening device 20 to the subject 10 via leads 34aand 34b. As illustrated in FIG. 3B, the first and second inputs 40a, 40bare further adapted to slideably and substantially sealably engage the probe connector 24a.

[0032] As illustrated in FIG. 3A, the acoustic coupling device 32 further includes a pair of acoustic attentuators 42a, 42bin communication with inputs 40a, 40b. The attenuators 42a, 42bare preferably adapted to provide at least first and second reductions in stimulus (i.e., signal) amplitude, respectively. In a preferred embodiment of the invention, the first and second reductions in stimulus amplitude are substantially equal.

[0033] According to the invention, various attenuators 42a, 42bmay be employed within the scope of the invention to provide the first and second reductions in stimulus amplitude. Such attenuators include conventional orifices, tubing lengths and other acoustic impedance devices, which are incorporated by reference herein.

[0034] Referring back to FIG. 3A, disposed on the opposing end of each attentuator 42a, 42band in communication therewith are primary stimulus input leads or tubes 52a, 52b. Also disposed proximate each attentuator 42a, 42bare first and second microphones 44a, 44b. The microphones 44a, 44bare in communication with the coupling device control means 46, which is adapted to control the operation (e.g., activation) of the acoustic coupling device.

[0035] According to the invention, the microphones 44a, 44bare positioned and adapted to monitor the primary stimulus input (i.e., acoustic stimulus signal) presented to the attentuators 42a, 42b. Each of the microphones 44a, 44bare also preferably adapted to provide at least a first signal to the control means 46 indicative of the presence of the stimulus. In response to the first signal(s), the control means 46, in the instant embodiment, would activate the coupling device 32 (i.e., on/off switch).

[0036] As illustrated in FIG. 3A, a first pair of input and output leads 52a, 54a, which are preferably encased in a cable housing 53 (shown in phantom), are in communication with a first earpiece 36aand a second pair of input and output leads 52b, 54b, which are similarly encased in a cable housing 53, are in communication with a second earpiece 36b.As illustrated in FIG. 5, each earpiece 36a, 36bis provided with an input and output lumen 37a, 37badapted to slideably receive a respective one of the input 52a, 52band output 54a, 54bleads.

[0037] In operation, a stimulus is presented to each of the subject's ears via input leads 52a, 52band earpieces 36a, 36b. The stimuli are sensed and substantially simultaneously transmitted into and through leads 52a, 52band communicated to microphones 50a, 50bvia output leads 54a, 54b. The microphones 50a, 50bprovide at least second and third signals in response to the detected (or response) stimuli, which are communicated to the monitoring means 48 of the invention.

[0038] According to the invention, the monitoring means 48 includes means for storing at least one stimulus amplitude indicative of an unacceptable response signal and means for comparing the unacceptable response signal to the response signal (i.e., detected stimulus or stimuli) from the subject 10. Various monitoring means, such as a conventional processor and comparator, may be employed within the scope of the invention. In a preferred embodiment, the monitoring means 48 comprises an A/D converter.

[0039] According to the invention, the monitoring means 48, in response to the second and third signals, is adapted to provide a plurality of signals, including at least a fourth signal indicative of an acceptable stimulus amplitude and a fifth signal indicative of an unacceptable stimulus amplitude.

[0040] In a preferred embodiment of the invention, at least one of the monitoring means signals are communicated to the coupling device display means 60. According to the invention, the display means 60 is adapted to provide a visual indication of the stimulus quality in response to the monitoring means signals.

[0041] As will be appreciated by one having skills in the art, various display means may be employed within the scope of the invention. In a preferred embodiment, the display means 60 comprises a conventional light emitting diode (LED) assembly.

[0042] Thus, by way of example, in response to the fourth signal referenced above, the display means 60 would illuminate a “green” light. In response to the fifth signal, the display means 60 would illuminate a “red” light.

[0043] Referring now to FIG. 4, there is shown an additional embodiment of the acoustic coupling device, designated generally 33. In this embodiment, the device 33 further includes a pair of signal generators (or reproducers) 58a, 58badapted to provide the desired amplitude of the stimulus.

[0044] As illustrated in FIG. 4, the signal generators 58a, 58bare in communication with the control means 46. According to the invention, the monitoring means 48 is also in communication with the control means 46. Thus, in operation, the monitoring means 48 would preferably provide at least sixth and seventh signals to the control means 46 indicative of the quality (or amplitude) of the stimulus signals detected by the microphones 50a, 50b, respectively. The control means 46, in response to the sixth and seventh signals, provides at least an eighth signal to signal generator 58aand at least a ninth signal to signal generator 58b. In response to the control means eighth and ninth signals, the signal generators 58a, 58bwould increase or decrease the stimulus amplitude to an acceptable level.

[0045] As illustrated in FIG. 4, the signal generators 58a, 58bare in communication with input leads 52a, 52b. The signal generators 58a, 58balso include output leads 52c, 52dthat are in communication with the first and second inputs 40a, 40b.

[0046] According to the invention, each of the noted audiometric coupling devices 32, 33 includes a pair of earpieces 36a, 36bthat are adapted to be placed proximate or, more preferably, within the cavity of the subject's ear (i.e., one earpiece per ear) and engage the input and output leads 52a, 52b, 54a, 54bof the coupling device 32 (see FIG. 5). The earpieces 36a, 36bare preferably constructed out of a flexible polymeric material, such as low-density polyurethane.

[0047] As discussed, the earpieces 36a, 36bare provided with input and output lumens 37a, 37bthat are adapted to slideably receive a respective one of the input 52a, 52band output 54a, 54bleads. Thus, after use, the earpieces 36a, 36bcan be readily removed and replaced.

[0048] As will be appreciated by one having skill in the art, various configurations of the “low-cost” earpieces 36, such as the earpieces shown in FIGS. 6A and 6B, can be employed within the scope of the invention to provide an acceptable level of sealable engagement proximate the subject's ear canal.

[0049] It will be appreciated that the present invention may be employed with virtually all conventional hearing screening devices, such as the ALGO 1E™ and ALGO 2 hearing screening systems available from Natus Medical, as well as acoustic emission based systems.

[0050] Without departing from the spirit and scope of this invention, one of ordinary skill can make various changes and modifications to the invention to adapt it to various usages and conditions. As such, these changes and modifications are properly, equitably, and intended to be, within the full range of equivalence of the following claims.