Hearing profile test system and method

Examples of systems and methods for profiling the hearing ability of a consumer are disclosed. One example includes a personal computer and a handheld device configured to produce calibrated acoustic output at suprathreshold levels above 20 db HL, and at step levels of 10-20 decibels, and presented test frequency bands across an audiometric frequency range from 400 to 8000Hz. The consumer's minimal audibility levels are registered, and a hearing profile score is presented to indicate hearing ability and hearing aid candidacy. In some embodiments, band-limited natural sounds are presented. Systems and methods disclosed herein, with considerations for noise present in the consumer's environment, allow for rapid calibrated hearing profiling, using a standard personal computer and minimal hardware, thus particularly suited for self-testing outside clinical environments such as at home or the office.

TECHNICAL FIELD

Examples described herein relate to methods and systems of hearing testing, particularly for rapidly profiling the hearing ability of a person, and for determining hearing aid candidacy. This application is related to U.S. patent application Ser. No. 12/878,928, titled, “CANAL HEARING DEVICE WITH DISPOSABLE BATTERY MODULE,” issued as U.S. Pat. No. 8,467,556, U.S. patent application Ser. No. 13/424,242, titled, “BATTERY MODULE FOR PERPENDICULAR DOCKING INTO A CANAL HEARING DEVICE,” issued as U.S. Pat. No. 8,855,345; U.S. patent application Ser. No. 14/011,604, titled, “HEARING AID FITTING SYSTEMS AND METHODS USING SOUND SEGMENTS REPRESENTING RELEVANT SOUNDSCAPE,” issued as U.S. Pat. No. 9,031,247; U.S. patent application Ser. No. 14/011,581, titled, “INTERACTIVE HEARING AID FITTING SYSTEM AND METHODS,” issued as U.S. Pat. No. 9,107,016, and pending U.S. patent application Ser. No. 14/011,607, titled. “ONLINE HEARING AID FITTING SYSTEM AND METHODS FOR NON-EXPERT USER,” filed on Aug. 27, 2013; all of which are incorporated herein by reference in their entirety for any purpose.

BACKGROUND

Pure tone audiometry is the gold standard for hearing assessment. It relies on identifying the threshold of hearing for an individual, generally using tonal sounds generated by instrumentation designed for clinical use by a hearing professional. The instrumentation and accessories for standard hearing tests are generally specialized electro-medical devices for use in a clinical setting. For example, to obtain a valid threshold test and an audiogram report, tests are generally performed in specialized sound-isolated rooms, often referred to as a “sound room,” to reduce noise levels present in the environment generally to that below the threshold of normal hearing. The combined cost of a sound room and clinical instrumentation for standard audiogram testing can easily exceed $20,000.

Performing a hearing assessment is generally not practical for lay consumers to self-administer, particularly in their home or office setting. Even in quiet room environments, noise levels typically exceed the maximum level required for accurately determining the threshold of hearing. Another limitation for self-administration of a hearing test at home is the complexity associated with the test procedure, which can be perplexing and time consuming for a lay person.

Current hearing evaluation methods and associated reports are generally designed for administration and interpretation by hearing professionals, such as an audiologist, an otolaryngologist, a hearing aid dispenser, etc. Standard audiogram results are generally of little value to a lay consumer and generally present irrelevant information pertaining to hearing aid candidacy. The audiogram test report, generally considered the standard form for hearing assessment and hearing aid prescription, is technical and not suitable for interpretation by a potential hearing aid consumer. For example, a standard audiogram report generally presents a person's hearing sensitivity for tonal sounds from −10 to 110 dB, inversely displayed, versus test frequencies from 125 to 8000 Hz. The hearing sensitivity for each frequency may also be tabulated in other audiogram forms. However, since these reports were designed mainly for clinical diagnostics and interpretation by a professional, they are generally not useful for a lay consumer, particularly for indicating hearing aid candidacy. Furthermore, determining the hearing ability in certain ranges, such as −10 to +15 dB HL, is generally not relevant to a person's ability to carry on normal conversations. Another limitation is the irrelevance of audiometric tonal sounds, which generally do not represent real life sounds. Another barrier for self-performed hearing assessment is related to the aforementioned cost, complexity and inaccessibility of standard hearing test instruments.

To circumvent some of the limitations of standard hearing evaluation methods, automated, computer-based hearing evaluation methods have been proposed, including self-administered online tests using personal computers. These tests are often inadequate, however, due to their inaccuracy, often caused by audio characteristics of consumer electronics not meeting the standards of audiometric testing. For example, consumer electronics, such as a sound card, may introduce unacceptable total harmonic distortion (THD), unpredictable frequency response, excessive signal noise, and/or excessive cross-over distortion. The sources of adverse audio characteristics can be attributed to the sound card, the speaker, consumer headphones, cabling, connectors, etc. In addition to the aforementioned obstacles related to audio characteristics, the calibration of acoustic signals emanating from a consumer transducer (a consumer earphone, for example) represents a daunting challenge, preventing accurate hearing evaluation by the lay consumer using a personal computer, or a personal electronic device.

Hearing screening tests offer basic hearing assessment for individuals on the basis of a pass or fail criteria. Generally speaking, these tests are administered by a hearing professional or a nurse, using a portable instrument, which produces a limited set of test stimuli often at a predetermined level between 20 and 40 dB HL depending on the age of the group being tested. These tests generally vary according to the guidelines of the agency, state, and country. Similar to standard audiometric evaluations, tonal and narrow-band noises are generally presented to administer the hearing screening test. One major drawback of current hearing screening methods is the lack of sensitivity and specificity for determining the hearing ability and indicating hearing aid candidacy. As a result, “failed” subjects are generally referred to a hearing professional for further hearing assessment prior to hearing aid candidacy assessment and hearing aid fitting.

SUMMARY

The present disclosure describes example systems and methods for calibrated evaluation of a consumer's hearing ability and hearing aid candidacy, without requiring clinical instrumentation and professional settings. In some embodiments, the hearing evaluation uses standard personal computers in conjunction with an audio signal generator device configured to generate calibrated audio signals to administer a rapid hearing profile test in the consumer's environment, such as the consumer's home or office. In some embodiments, the audio signal generator device may be handheld and worn on the body or placed on a table during the hearing test. The hearing profile test presents a sequence of supra-threshold test stimuli, generally above 20 dB HL with increments in the range of 10-20 decibels, up to test levels of approximately 70-80 dB HL. The test signals may be presented in frequency bands in the range of 400-8000 Hz. The consumer's minimum audibility response within the suprathreshold sound level range presented at each test frequency band may be registered using a personal computer, which may comprise a smartphone or a tablet computer. The personal computer executes a hearing profile software application to implement the hearing profiling method described herein, and to present a computed hearing profile score, indicting the general hearing ability and hearing aid indication. The hearing profile score may be whole or fractional, for example indicating approximately one of five discrete levels or categories of hearing ability. The entire evaluation process, including profiling, scoring and hearing aid indication, may take approximately less than 10 minutes, in one embodiment. The cost to a consumer may be less than $50, including minimal incremental hardware and software to administer the calibrated test using a personal computer virtually anywhere, including at home.

In an example embodiment, the acoustic stimuli presented are in the suprathreshold range of 30-80 dB HL, with a test increment of approximately 10 decibels, presented at frequency bands of 500, 1000, 2000, 4000 and 6000 Hz. The score may be computed based on minimal audibility level (MAL) within the suprathreshold range presented, and weighted by appropriate factors such as the speech intelligibility index (SII) as per American National Standards ANSI/ASA S3.5.

In one example embodiment, the delivery of the acoustic test signal from the hearing profile evaluation system may be provided by a standard consumer-type earphone with calibrated electroacoustic performance. The earphone may be provided with insert eartips, to occlude the ear canal and reduce the audibility of ambient background sounds present in typical room environments. By limiting the test presentations to suprathreshold levels, generally exceeding 20 dB HL, and using ear occluding eartips, hearing profiling may be performed in any reasonably quiet room environments, eliminating the cost and inconvenience of specialized earphones and clinical settings. In one embodiment, a microphone may be incorporated to sense the level of ambient background noise and adjust the hearing evaluation process accordingly. By reducing the range of presentation levels and test frequencies, increasing the test increment level to 10 dB or more, and providing a simplified scoring system, the lay consumer may be presented with an alternative hearing evaluation method that is easy to understand and correlate to hearing device candidacy.

In one embodiment, one or more natural sounds are presented as calibrated test signals. For example, a drum sound may be presented for testing the low frequency range of hearing, and a bird chirp sound may be presented for testing the high frequency range of hearing. The hearing profile test may be administered online with a hearing profile software application at least partially hosted by a remote server and executed by the consumer's own personal computer that is connected online to the remote server and to the handheld audio generator device at the consumer side. The online computerized hearing test system may be advantageous by offering online support during the hearing evaluation process. In one embodiment, a customer support personnel may send speech communications online from a customer support computer system into the test earphone. The customer support personnel may also use the customer support computer system to receive speech communications online from the consumer by the aforementioned microphone using Voice-Over Internet Protocol (VoIP) communications.

DETAILED DESCRIPTION

Certain details are set forth below to provide a sufficient understanding of embodiments of the invention. Some embodiments, however, may not include all details described herein. In some instances, some well-known structures may not be shown, in order to avoid unnecessarily obscuring the described embodiments of the invention.

The present disclosure describes example systems and methods, as shown inFIGS. 1-13, for profiling the hearing ability of a consumer and indicating hearing aid candidacy rapidly and inexpensively without requiring expensive equipment and clinical settings. Referring toFIG. 1, in one embodiment, the evaluation process uses a general purpose computing device, for example a standard personal computer10, in conjunction with a handheld device30configured to generate a calibrated audio signal31(also referred to herein as “test audio signal” and “audio signal”) to earphones40to administer a hearing test in the consumer's normal environment, such as the consumer's home or office. The personal computer10, the handheld device30, hearing profile software application50, and the earphones40may collectively form a computerized test system20(also referred to herein as “computerized hearing test system”). The computerized test system20presents a sequence of supra-threshold test stimuli41, generally above 20 dB HL, into the ear2of the consumer1. For reference purposes, 0 HL represents the threshold of hearing for normal hearing individuals, and suprathreshold refers to sound levels above the threshold of normal hearing. Also, 20 dB represents a significant increase over threshold levels, from the sound level perspective, as well as electrical signal requirements for the electrical audio signal31producing the acoustic test stimuli41. In various embodiments, the test stimuli41may be provided in step levels in the range of 10-20 dB, in contrast to standard audiometric test methods which specify 5 dB increments, for example as per ANSI/ASA 3.6 standard.

FIG. 2shows a smartphone embodiment of a computerized hearing test system with a handheld device30connected to smartphone15, executing a hearing evaluation application for self-administration. The user1follows instructions and registers audibility responses using the touch screen12of the smartphone15. Similarly, a hearing profile score72, hearing profile76(also referred to herein as “hearing ability”), and hearing aid candidacy79are presented to the user following the hearing profile test. The computerized hearing test system20may be implemented to enable rapid and sufficiently accurate assessment of a consumer's hearing ability in environments outside clinical setting, and to provide easy to understand scoring system with hearing ability scale75and hearing aid candidacy scale78.

In one embodiment, the acoustic test stimuli41may be presented at three or more frequency bands within the audiometric frequency range of about 400 to 8000 Hz. The consumer's minimum audibility level (MAL) within the suprathreshold (with respect to normal hearing) range of sound levels presented at each test frequency band may be registered using the personal computer's standard interface, such as a keyboard11, mouse, or touch screen12. The personal computer10may also be in the form of a smartphone15as shown inFIG. 2, or a tablet computer (not shown). A personal computer herein generally refers to any consumer computing device capable of executing a hearing profile software application50according to the teachings herein. After executing the hearing profile test (also referred to herein as “hearing test” and “hearing profile evaluation”), the consumer1may be presented with a hearing profile score72(FIG. 3) from a hearing profile score scale71, with each hearing profile score (HPS) corresponding to a hearing profile within hearing profile scale75, and hearing aid candidacy indication within hearing aid indication scale78. The levels within the hearing profiling system may be in the range of about 4-6 discrete levels or categories. Throughout this application, the term “consumer” refers to any person taking the hearing test and is interchangeable with other, similar terms, including but not limited to “user,” “person,” “client,” “hearing impaired,” “tester,” “test subject,” etc. The term “hearing aid,” is used herein to refer to all types of hearing enhancement devices, including medical devices generally prescribed for the hearing impaired, and personal sound amplification products (PSAP) generally not requiring a prescription or a medical waiver.

In some example embodiments, the suprathreshold level of acoustic test stimuli41may be limited to a range of about 30-80 dB HL, with level increments in a range of about 10-20 dB between consecutive stimuli, at multiple frequency bands within a range of about 500-6000 Hz. The hearing profile score,72for example, is generally based on a computation incorporating the minimal audibility levels at the test frequencies. The scoring computation may optionally incorporate, at least partially, frequency weighting factors, such as the speech intelligibility index (SII) as per ANSI S3.5 standard, as will be described in more details in an example below. In one aspect, the consumer1is offered a simplified scoring system for indicating hearing ability and hearing aid requirements.

In some embodiments, the acoustic test signal41from the computerized hearing test system20may be delivered via an earphone40with an eartip47(FIG. 4), also referred to here as ear canal “insert,” which occludes the ear canal and minimizes the adverse effects of ambient background noise5(FIG. 1) present in room environments during the hearing profiling process evaluation. The insert47is connected to the earphone earpiece46incorporating a transducer (not shown) within. In the preferred embodiments, the eartip47provides at least 5 dB of noise attenuation, within the audiometric range of 500 Hz to 6,000 Hz. Noise herein generally refers to sounds which may compete with the test stimuli41presented to the ear2by the earphone40, which may be insert type (as shown) or circumaural headphone (not shown). The insert47may be removable and offered in assorted sizes, for example with a relatively large eartip48as an alternative for individuals with relatively larger ear canals. In some embodiments, an assortment of 3-4 eartips may be provided, to ensure proper fit in variety of ear canal sizes. By presenting calibrated acoustic test signals41at suprathreshold levels generally exceeding 20 dB HL, and in combination with an occluding earphone40, a hearing profile evaluation may be administered in a typical room environment, as is further described below.

To further mitigate the effects of potentially excessive noise in certain room environments, a microphone35(FIG. 1) may be incorporated within the handheld device30to sense room sound5in the vicinity of the user1. The hearing profile test process may then be adjusted according to the noise condition, for example by delaying the presentation of test stimuli41during a noise burst, or by halting the test process in the presence of persistent or excessive noise.

In some embodiments, the handheld device30is placed generally on the user's body in proximity to the ear2, for example on the torso3area as shown inFIGS. 1 and 2. In some embodiments, the handheld device30may be affixed to the user's shirt or jacket with a clip (not shown) or held by a necklace (not shown). The computerized hearing test system20and methods thereof allow rapid and accurate hearing profiling for a lay person with minimal hardware by leveraging their own personal computing device while presenting calibrated test audio signals31by the handheld device30. In some embodiments, the computerized hearing test system20is designed primarily for self-administration. However, it should be understood that assistance may be provided for certain individuals, for example those with limitations related to aging, heath condition, or mental capacity. The handheld device30, in some embodiments, includes a USB interface38for interfacing with, and control by, a personal computer10, and in some cases for streaming of digital audio representing test signals or audio instructions from the personal computer10. Digital audio files representing test stimuli, as well as calibration constants associated with calibrated test stimuli, may be stored within the handheld device30, within the client personal computer10, on a remote server60(FIG. 10), or generally anywhere on the Internet “cloud”65(FIG. 10). The handheld device30houses audio signal generator36(also referred to herein as “digital audio system”), and includes programmable audio amplifiers to provide calibrated test audio signals31. The digital audio system is generally independent of the personal computer10audio capabilities, and may be configured to provide calibrated audio signals31regardless of the computer platform used by the consumer1. This allows for predictable audio characteristics conforming to accepted standards, for example as per ANSI/ASA 3.6. In preferred embodiments, a single-chip digital audio system is employed within the handheld device20to convert digital audio data from the personal computer10to a predetermined level of audio signal31for delivery to the earphone40, generating a calibrated test stimuli41signal to the ear2. The term “calibrated” herein generally refers to the terms “known,” “determined,” “predetermined,” and similar terms to describe an electrical or an acoustic signal having predicted characteristics, whether by a design or by a calibration process, to conform to a standard or a design specification.

FIG. 4shows one embodiment of a system for calibrating a standard earphone40using a standard 2-cc coupler83and a sound level meter80. The eartip47or48may be removed from the earphone earpiece46and coupled to the 2-cc coupler, using an earphone-coupler interface85. A microphone section84of the sound level meter80is typically inserted into the 2-cc coupler cavity for calibrating the sensitivity of the earphone earpiece46, using the sound level measured and presented at the display81of the sound level meter80. The calibration of the earphone40is preferably performed by the manufacturer or calibration service provider for the handheld device30, and generally not of concern for the consumer1. The consumer1may plug the audio connector42of the earphone40into the handheld device30and plug USB connector38of the handheld device30into the personal computer10. The consumer1may then begin the testing, using the hearing profile software application50(FIG. 11) provided to the consumer1for execution by the personal computer10, and by the handheld device30, which may be configured to deliver calibrated test signals31.

In one embodiment, one or more natural sounds may be employed as test stimuli41to engage the consumer with sounds relevant to the human hearing experience. In contrast to traditional methods, which employ tonal sounds, natural sounds represent sounds audible in normal listening experiences, such as human speech, music, animal sounds, bird chirp, wheel squeak, etc.

In an example embodiment, a drum snare sound recording may be used to test the hearing ability of the consumer1at a relatively low frequency range of audible sound, as shown inFIGS. 5(waveform) and6(frequency spectrum). A drum snare sound generally has significant content in the low frequency portion of the human auditory range, for example around 500 Hz. With further processing by an audio processing software, for example AUDACITY® for Windows, the original drum snare recording waveform may be modified to result in a frequency response peaking at approximately 500 Hz and with reduced frequency content outside the 500 Hz frequency band as shown inFIG. 6. Alternatively, a hammer sound may demonstrate similar spectral characteristics and may be employed for hearing testing in a low frequency range.

In another example, a bird chirp sound recording may be employed for testing hearing of the consumer1at a relatively high frequency range, as shown inFIGS. 7(waveform) and8(frequency spectrum). A bird chirp sound generally has significant content in the high frequency portion of the human auditory range, for example around 6000 Hz. The original bird chirp recording may also be filtered by an audio processing software to produce a test signal substantially in the high frequency range, for example around 6000 Hz frequency band, as shown inFIG. 8.

FIG. 9shows a simplified example flowchart for an automatic hearing evaluation process for determining the minimum audibility level (MAL) of the consumer1within the range of the suprathreshold sound levels presented. As shown in the flowchart with operations110-130, starting with determining MAL at 1000 Hz. (operation110), a signal level of 50 dB HL may be initially set (operation116) and test stimuli41is presented at 50 dB HL (operation117) to the consumer1. The response from the consumer1is then determined by operation118and if no response is registered by the computerized hearing test system20within a time window, typically 1 to 1.5 seconds from the end of the stimuli period, the “current level” of the test stimuli41is incremented by 20 dB HL, up to a maximum level of 80 dB HL for example (operation119) and the test stimuli41is then presented to consumer1at the increased level (operation117). When a response is detected in operation118, an MAL value is recorded (operation120) for subsequent verification by operations120-126whereby the test signal level is decremented by 10 dB (operation121) and presented (operation122) for response determination (operation123). If a response is not registered at operation123, the test stimuli level is incremented by 10 dB (operation124) and the test stimuli is presented (operation122) with the increased level, and the process is repeated if necessary, until a response is registered at operation123. The MAL for a test frequency is considered “found” (operation126) generally when the computerized hearing test system20detects two consumer responses at the same presentation level as determined by operation125, which compares a currently registered response level with a previously recorded MAL. If the current response level does not match the previously recorded MAL, a new MAL value is set and recorded (operation120) and the signal level is decremented by 10 dB (operation121) until an MAL is determined (operation125). In the preferred embodiments, the step size for consecutive test presentations is within the range of 10-20 dB.

The process for determining MALs for all test frequencies (operations110-114) may be sequenced as in shown inFIG. 9, or interleaved (not shown), either randomly or at a predetermined interleave sequence. Interleaving may minimize predictability of test process sequence by the consumer1and may improve the reliability of the test. A final verification process (operation115) at one frequency, typically at 1000 Hz, is preferably administered to assess the reliability of the user's responses. For example by re-presenting a 1000 Hz test stimuli41(operation127) at the MAL previously determined in operation110, and determining if the consumer1is responding consistently at this level (operation128), and to determine either a reliable “valid test” (operation130) or inconsistent “invalid test” (operation129). It should be understood that variations of the aforementioned example hearing evaluation process and algorithm thereof are possible and may be advantageous.

Known attempts to address the issues and limitations of current audiometry methods include providing embodiments of automatic hearing testing and hearing aid programming integrated in a unitary headset instrument. These embodiments offer conventional test stimuli to compute standard prescriptive formulae to program into a hearing aid. Known attempts also include online home testing using the consumer's own personal computers and the consumer's own headphones or the computer's speakers. To circumvent issues related to signal quality and calibration, online tests generally employ signal-in-noise conditions, mainly to detect the person's ability to hear in the presence of noise. Although they may be valuable in assessing the hearing ability for certain types of losses, these signal-in-noise tests fail to indicate the level of hearing loss, and are considered as screening tools requiring further assessment by a hearing professional using diagnostic hearing assessment tools.

In an online embodiment of the hearing evaluation method of the present invention shown inFIG. 10, a hearing test software application61is hosted by a remote server60and executed locally by the consumer's personal computer10, as a client computer connected online to the server60via the Internet65. The hearing test software application50executed by the computer10is at least partially hosted by the server60, in the example online embodiment. The results of the hearing evaluation, including the hearing profile store, may be stored in a remote database.

The online computerized hearing test system may further offer online customer support by connecting to a customer support computer system66operated by customer support personnel68. The customer support personnel68may communicate with the consumer1by a headset67, including a microphone to stream instructions from customer support computer66to the consumer1. For example, voice over IP (VoIP) may be used to stream instructional audio to the client computer10, to the digital audio system36of the handheld device30via the USB connectivity38, and ultimately as audible stimuli41to the consumer's ear2via the earphone40. Instructional audio may include the speech of customer support personnel68, recorded or generated audio massages from a server60or customer support computer66. Speech communication from the consumer1may also be transmitted to the customer support personnel68by the reverse process, using the microphone35of the handheld device30, or another microphone incorporated in the computerized hearing test system20.

FIG. 11shows an example user interface (UI)50for an online embodiment of the hearing evaluation method, employing a web browser to execute a server hosted hearing profile software application. The UI50shows UI elements, including user instructions51, test pause control52, test presentation status56, test process status53, online connection status54, and handheld device20connection status55. In this embodiment of the user interface50, the user1is generally instructed to listen to the calibrated test sounds41presented and press the space bar of the keyboard11(or a key on the touch screen12) when the sound41is heard. In one embodiment, the browser-based application operates in conjunction with a client application, which provides access to, and control of, the handheld device30.

FIG. 12shows an example representation of the hearing profile scoring UI70, showing hearing profile score72, hearing profile score scale71, and hearing ability76and hearing aid indication79. Contrasting the hearing profiling system disclosed herein with standard audiogram reports, which display the sensitivity of hearing from −10 to 110 dB and in a reverse order without indicating hearing ability or candidacy, the hearing profile score72and corresponding hearing ability76and hearing aid candidacy79, indicates the general ability to hear from “Normal”73to “Extensive”77, suggesting professional assessment and/or intervention. Hearing aid candidacy79may be computed at least partially from the hearing profile score, and in some cases other factors may also contribute.

FIG. 13shows an alternate embodiment of the hearing profile scoring scale71, whereby the scale is primarily descriptive, and a fractional hearing profile score90is presented in conjunction with the descriptive scale. In some examples, the fractional hearing profile score90may be presented as an overlay, that is on top of the scoring scale71, in order to provide the consumer1with a more precise score while also pointing to general descriptive context. According to various alternative embodiments, suitable variations of the scoring system and method and corresponding indications may be made, such as reversing the order of the scoring scale71, with level 1 representing “Normal Hearing” and the highest level representing worst hearing ability. Alternatively, alphanumeric character representation, such A, B, C, etc., may be used to represent the hearing ability. In the preferred embodiments, the scoring levels may be limited to 4-6 categories. The web page UI70ofFIG. 12also shows a hearing aid recommendation section74, describing product and pricing options to the consumer.

In contrast to conventional audiometric test methods and reports, the systems and methods disclosed herein simplify and expedite the test process by eliminating various redundancies and limiting the hearing evaluation to test signals relevant to hearing aid candidacy and fitting, generally at levels above 20 dB HL and frequencies above 500 Hz and up to 6,000 Hz. This is particularly applicable when considering the fitting systems and methods that use subjective assessment by the consumer for determining hearing aid fitting parameters during the fitting process. By eliminating testing below 500 Hz, the adverse effects of low frequency noise commonly present in room environments may be substantially mitigated.

Experiment

The following experiment was conducted to assess and validate the hearing profile test in normal room environments according to the teachings disclosed herein. Sound measurements were taken in an office with two personal computers operating and the test instruments used to conduct the experiment. Fan noise from the computers and street noise were noticeably audible by non-occluded ears. The measurements were taken approximately 4 feet away from the nearest computer. The room noise level was measured using a 2-channel spectrum analyzer (Stanford Research model SR 785), two probe tube measurement systems (ER-7 manufactured by Etymotic Research) and an integrating sound level meter (Model 2200 manufactured by Quest). This experiment is reported here by way of example and to facilitate understanding and appreciation of the system and methods described herein. Inclusion of this experiment here is in no way intended to represent that all experiments performed did or will achieve like results.

Room noise was initially measured by the sound level meter, indicating average noise level of about 44 dB SPL. Using the spectrum analyzer and the probe tube system, the average noise level in ⅓ octave bands was measured for frequencies between 500 and 6000 Hz frequencies as tabulated in Row-A of Table 1. The attenuation across the earphone40(model TMG-ACD) was also measured by the ER-7 probe tube measurement with the eartip snuggly inserted in a SILICONE® rubber ear model, with one probe placed inside the ear model and the other outside to measure the deferential sound pressure level across the earphone in the ear model. The resultant attenuation of the earphone eartip was tabulated in Row-B.

Row C shows the maximum allowable noise level in ⅓ octave bands for audiometric testing of threshold levels according to ANSI 3.1 in the condition of ears not covered. Row-D estimates the permissible noise level for each frequency band according to the teachings of the present invention, with a presentation level 30 dB above normal threshold of hearing levels. The permissible level for present method was estimated by adding 30 dB to the permissible noise levels according to the ANSI standard for threshold testing, and the attenuation of the earphone eartip occluding the ear.

Accordingly, the permissible noise level (D) can be calculated from the equation:
Earphone Attenuation(B)+Allowed noise level per ANSI(C)+30 dB

TABLE 1Frequency in Hz.5001000200040006000HzHzHzHzHzA—Room Noise in dB SPL30.029.530.132.033.3B—Earphone Attenuation in dB9.813.318.94.89.1C—Allowed Noise dB SPL per ANSI118968D—Permissible Noise in dB SPL50.851.357.940.847.1(est.)E—Estimated Noise Margin in dB20.821.827.88.813.8SPL

ANALYSIS AND CONCLUSION FOR EXPERIMENT

Testing the hearing ability at or above 30 dB HL across the audiometric frequency range of 500 to 6000 Hz. is possible in reasonably quiet environments such as an office, even in the presence of computers and other instruments using the principles of the present invention. There was a substantial margin of noise at virtually all test frequencies, with the exception of 4,000 Hz having only an 8.8 dB margin. This is possible due to relatively poor sound attenuation of the eartip at this particular frequency. It should be understood that noise levels are expected to vary considerably across room environments due to room acoustics, noise sources, distance and the position of the consumer with respect to noise sources. However, these variations are expected to be substantially mitigated by testing at suprathreshold levels above 20 dB, and particularly at 30 dB HL as in this example.

Asymmetric hearing losses represent a challenge to hearing assessment, whereby masking sounds may be required for the non-test ear. Masking is a task not easily understood or implemented by a lay person. However, the system and methods disclosed herein are well suited to automatically introduce masking sounds to the non-test ear in order to mitigate cross-over errors in asymmetrical hearing losses. For example, by automatically delivering a narrow band, or broad band noise to the non-test ear. In the example embodiments, test sounds are presented at frequencies of 500, 1000, 2000, 4000 & 6000 Hz, preferably with at least one natural sound as disclosed above. Test signals may also be tonal such as warble tones, mixed tones, or band-limited noise. Pure tones may also be presented but are generally considered less desirable. Masking of a non-test ear using a stimulus of predetermined level may also mitigate the adverse effects of room noise, for example by presenting a masking noise to the test ear to compete and override ambient noise.

The following method and computation formula represents an example for computing a hearing profile score (HPS). A scoring scale from 0 to 5 is assigned for each test levels from 30 to 80 dB HL (Table 2), incrementing by 10 dB, for 5 test frequencies of 500, 1000, 2000, 4000 and 6000 Hz. The hearing profile score is then computed according to the minimum audible level (MAL) values according to weighting factors from the Speech Intelligibility Index per ANSI S3.5-1997: “Methods for Calculation of the Speech Intelligibility Index”. The weighting factor for 250 Hz. was added to the value for 500 Hz weighting since hearing losses at these adjacent frequency bands is generally similar for the hearing loss population of interest, and since there is no testing at the frequency of 250 Hz in the example embodiment. The weighting factor for 8000 Hz was substituted for 6000 Hz, also since no testing occurs at 8000 Hz in this example. In other examples, testing at 8,000 Hz may be included.

The hearing profile score is then computed by adding weighted scores for all frequency bands, and scaling if necessary to yield the maximum index level employed, being 5 in this case. The fractional hearing profile score90(FIG. 13) in the example tabulated below is 3.17 out of 5, which may be presented as the hearing profile score71of 3 when rounded to the nearest whole digit.

Although examples of the invention have been described herein, variations and modifications of this exemplary embodiment and method may be made without departing from the true spirit and scope of the invention. Thus, the above-described embodiments of the invention should not be viewed as exhaustive or as limiting the invention to the precise configurations or techniques disclosed. Rather, it is intended that the invention shall be limited only by the appended claims and the rules and principles of applicable law.