U.S. patent application number 11/378501 was filed with the patent office on 2006-09-21 for personal hearing evaluator.
This patent application is currently assigned to InSound Medical, Inc.. Invention is credited to Adnan Shennib.
Application Number | 20060210090 11/378501 |
Document ID | / |
Family ID | 23582431 |
Filed Date | 2006-09-21 |
United States Patent
Application |
20060210090 |
Kind Code |
A1 |
Shennib; Adnan |
September 21, 2006 |
Personal hearing evaluator
Abstract
A hand-held device includes an audio transducer (i.e., speaker)
for delivering acoustic test stimuli to a test subject within the
direct sound field range of the device. The device accurately
delivers multi-level and multi-frequency test stimuli for the
subjective response by the test subject holding the device. An
ultrasonic position sensor within the device determines the
position of the device with respect to the head or a portion of
interest of the head of the test subject while the device is being
held. The acoustic test stimuli are controlled and regulated based
on the position of the device with respect to the test subject so
that accurate levels of test stimuli are presented only when the
device is within a proper range and irrespective of its exact
position with respect to the test subject's head.
Inventors: |
Shennib; Adnan; (Fremont,
CA) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
InSound Medical, Inc.
Newark
CA
|
Family ID: |
23582431 |
Appl. No.: |
11/378501 |
Filed: |
March 16, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09400151 |
Sep 21, 1999 |
7016504 |
|
|
11378501 |
Mar 16, 2006 |
|
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Current U.S.
Class: |
381/67 ;
381/312 |
Current CPC
Class: |
H04R 25/558 20130101;
A61B 5/121 20130101; H04R 25/30 20130101; H04R 25/70 20130101 |
Class at
Publication: |
381/067 ;
381/312 |
International
Class: |
A61B 7/04 20060101
A61B007/04; H04R 25/00 20060101 H04R025/00 |
Claims
1. A hand held device for performing sound field hearing testing,
the device comprising: an audio transducer configured to produce
acoustic test stimuli to a test subject within a direct sound field
range of the audio transducer; a contactless position sensor system
configured to remotely measure a distance of the device with
respect to the head or part thereof of the test subject; and means
for adjusting characteristics of the acoustic stimuli responsive to
the position sensor system, the adjustment means configured to
produce a substantially constant acoustical perception at the
subject's ear irrespective of device position or test mode.
2. The device of claim 1, wherein the adjusting means is configured
to adjust the acoustic stimuli responsive to ambient noise.
3. The device of claim 1, wherein the device is configured for
operation by a test operator assisting the test subject.
4. The device of claim 1, including means for performing the
hearing evaluation in an unaided condition in which the test
subject is not wearing a hearing aid.
5. The device of claim 1, including means for performing the
hearing evaluation in an aided condition in which the test subject
is wearing a hearing aid.
6. The device of claim 5, including means for performing the
hearing evaluation in the aided condition to verify functionality
of the hearing aid worn by the test subject.
7. The device of claim 5, including means for performing the
hearing evaluation in the aided condition to adjust at least one
parameter of the hearing aid.
8. The device of claim 1, further comprising means for delivering
at least one of the acoustic test stimuli within the soft level
listening range of normal hearing individuals.
9. The device of claim 8, wherein the soft level listening range is
between 20 and 40 dB HL.
10. The device of claim 1, further comprising means for delivering
at least one of the acoustic test stimuli within the comfortable
level listening range of normal hearing individuals.
11. The device of claim 10, wherein the comfortable level listening
range is between 45 and 65 dB HL.
12. The device of claim 1, wherein the contactless position sensor
system comprises at least one of an optical transducer, an acoustic
transducer or an ultrasonic transducer.
13. The device of claim 1, wherein the contactless position sensor
system comprises means for determining if the device is within an
operable range and orientation with respect to the head or part
thereof of the test subject.
14. The device of claim 1, wherein the contactless position sensor
system comprises a transmitting transducer and a receiving
transducer.
15. The device of claim 1, further comprising interface means for
connecting a remote instrument to the device for remotely operating
the device.
16. The device of claim 15, wherein the interface means comprises
at least one of the Internet or a wireless connection.
17. A method of remotely evaluating a test subject's hearing, the
method comprising: selecting an acoustic test stimuli to test the
hearing of the test subject; signaling the selected test stimuli
from a remote location with respect to the test subject to a
hand-held device having an interface and an audio transducer;
delivering the acoustic test stimuli to the test subject with the
hand held device oriented toward the subject's head or part thereof
of interest; registering a user response to the test stimuli; and
signaling the user response to the remote location.
18. The method of claim 17, wherein the test stimuli and user
response are signaled over at least one of the Internet or a
wireless connection.
19. The method of claim 17, wherein the user response is registered
using a response key on the hand held device.
20. The method of claim 17, wherein the test stimuli are selected
using a computer.
21. The method of claim 17, wherein the test stimuli comprise an
audiogram test including six or more frequencies.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/400,151 (Attorney Docket No.
022176-000700US), filed on Sep. 21, 1999, the full disclosure of
which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] A. Technical Field
[0003] The present invention relates generally to air-conduction
hearing evaluation, and more particularly, to portable hand-held
hearing testing and hearing aid fitting.
[0004] B. Description of the Prior Art
[0005] Air-conduction hearing evaluation involves the presentation
of airborne sounds (test stimuli) to the ears of a test subject.
The evaluation may involve threshold measurements whereby the
threshold of hearing is determined at various frequencies, or
suprathreshold measurements whereby loudness perceptions above
threshold are determined. Suprathreshold testing include most
comfortable loudness (MCL), uncomfortable loudness (UCL) and
dynamic range measurements. A variety of test stimuli types are
employed in audiological testing including pure tones, speech, and
a variety of noise-based signals.
[0006] Test stimuli in air-conduction testing are emitted from a
speaker to travel in air and ultimately reaching the eardrum. A
speaker is typically positioned directly on or within the ear as in
the case of circumaural earphones (headphones) and insert
earphones. Alternatively, in sound field testing, a speaker is
placed at a distance from the ear of the test subject in a test
room (See American National Standard, specification for Audiometry,
ANSI S3.6-1996).
[0007] Sound field evaluation generally involves bulky
instrumentation, complex calibration procedures and require
specialized test rooms. Furthermore, precise positioning of the
subject with respect to a speaker is necessary in order to minimize
errors in the intensity level of the sound at the ear. These errors
are also caused by reverberations commonly found in test rooms (see
Sandlin, R, Handbook of Hearing and Amplification, Ch. 6. pp
147-164, Singular Publishing group, 1995). FIGS. 6-3 of Sandlin,
for example, demonstrate how large the variability of pure tone
sound field measurement can be for small changes in distance
between the subject and the speaker.
[0008] In standard sound field audiometry, the subject is typically
placed approximately at 1 meter (m) from the speaker.
Unfortunately, the reverberant component of sound at 1 millimeter
(mm) is significant as shown in FIGS. 6-2 of Sandlin. The use of
anechoic test rooms to eliminate reverberant sounds is extremely
expensive and thus not employed in standard audiological test
setups.
[0009] To minimize the effect of reverberant sounds, the subject
should be positioned within the direct field of sound, which is
typically within 70 centimeters (cm) from speaker. This causes the
direct sound in the direct field to be dominant with respect to
reverberant sound reflected from nearby objects in the room (i.e.,
walls, ceiling, floor, equipment, etc.). However, maintaining a
precise seating arrangement within 70 cm of a speaker presents many
challenges related to subject movement, discomfort, and even
claustrophobia.
[0010] The utilization of probe tube microphone system to calibrate
and regulate presentation levels has been widely used for various
hearing evaluations (for example, see pp. 192-204 in Sandlin).
However, probe tube microphone instrumentation requires careful
positioning of the probe tube for each hearing evaluation step
performed. Furthermore, the use of microphone probe tube systems
adds considerable cost and complexity for the evaluation procedure,
not to mention the inconvenience of attaching and maintaining a
probe tube and its cabling for both the subject and the
clinician.
[0011] In headphone audiometry (TDH-3 9 type for example), the
distance between the test ear and the speaker is relatively stable
thus alleviating the problem of speaker-subject positioning
encountered in sound field audiometry. However, the headphone must
be fitted in a sealing manner in order to minimize errors due to
sound leakages that may occur at the headphone-ear contact area.
Insert earphones (ER-3A type for example) also require a good
sealing fit when inserted within the ear canal. Headphone and
insert earphones can be uncomfortable and cumbersome for many
individuals. Furthermore, headphone and insert earphones are
particularly problematic for aided evaluation (with a hearing aid
placed in the ear) because they generally interfere, physically and
acoustically, with the proper function of a worn hearing device.
Therefore, headphone and insert earphones are generally excluded
from aided evaluation. Other problems associated with headphones
and insert earphones include inaccuracies due to individual ear
size variability and cabling interference and damage.
[0012] Portable and hand-held hearing evaluation is advantageous
for conducting hearing testing outside the standard calibrated
audiological setups. However, due to the relatively large errors
associated with outside room acoustics, calibration,
speaker-subject positioning and ambient background noise, portable
and hand-held instruments tend to be limited to basic screening
evaluation, requiring follow up testing in a proper audiological
setup.
[0013] Review of State-of the-art in Related Hearing Device
Technology
[0014] Heller, J., in U.S. Pat. No. 4,567,881 describes a
combination otoscope and audiometer for performing audiometric
testing during otoscopic examination. Since the testing is
performed while the tip of the otoscope is inserted in the ear
canal, it is obviously not intended for aided evaluation whereby a
hearing aid is worn in the ear canal. Furthermore, an otoscope is
intended for use by a professional thus not suitable as a personal
hearing evaluator.
[0015] Shennib, A. in U.S. Pat. No. 5,197,332 describes a headset
hearing tester which is worn on the head for positioning a speaker
portion directly on the ear. As previously observed, headphone type
audiometry not only interferes with the proper function of most
hearing aids when worn, but is also bulky and uncomfortable for
many users.
[0016] Chojar in U.S. Pat. No. 5,081,441 discloses a hand-held tone
generator for generating an audible tone as a test for equalizing
binaural hearing aids. Chojar's device is limited to producing a
single tone at single level, thus clearly not suitable for
performing audiometric measurements. In fact, it is merely
concerned with ensuring a balanced binaural aided hearing.
[0017] Downs, M., in U.S. Pat. No. 5,291,785 describe a hand-held
portable device for testing infants for hearing defects. The device
produces a low intensity sound for eliciting a response and a high
intensity sound for eliciting reflex from the infant. Although
designed to produce multi-level acoustic stimuli, the device is
essentially a screening device for infants, thus not concerned with
presenting accurate stimulus levels at multiple frequencies, nor
concerned with aided evaluation. Furthermore, the device is clearly
not designed for self-testing.
[0018] Posen et. al., in U.S. Pat. No. 5,732,396 disclose a
hand-held screening device for generating various acoustic stimuli
at a distance set by a physical spacer incorporated into the
screening device. The spacer makes direct contact with the ear area
for positioning the speaker at 11/2 to 21/4 inches form the ear.
The screening device, with a spacer incorporated within, has the
advantage of providing a predetermined distance between the speaker
and the test ear. However, the direct contact of the device to the
ear area is not only awkward for audiometric testing, but is also
difficult to operate by an individual of limited dexterity in
self-testing scenarios. Furthermore, testing involving both ears
simultaneously (binaural mode) is not possible with such a
device.
[0019] There are numerous situations whereby it is desirable to
provide a hand-held hearing evaluator with accurate multi-level
test sounds. It is also desirable to provide a miniature instrument
with means for self-administered testing without resorting to an
expensive test performed by a hearing professional. In another
situation, it is desirable to have a personal hearing evaluator to
regularly verify the function of a worn hearing device. This is
important since hearing aids are notorious for being subject to
frequent damage and deterioration.
[0020] Therefore, it is a principal objective of the present
invention to provide a hand-held hearing evaluation device for
presenting multi-level and multi-frequency stimuli.
[0021] Another objective is to provide contactless means to
properly position a speaker with respect to a test individual for
accurate presentation of test stimuli.
[0022] A further objective is to provide a hearing evaluation
device with means to automatically calibrate the level of acoustic
stimuli presented.
[0023] A further objective is to provide an easy to use hand-held
hearing evaluator suitable for self-administration by a test
subject in either aided or unaided conditions.
BRIEF SUMMARY OF THE INVENTION
[0024] The invention provides a hand-held device comprising an
audio transducer (i.e., speaker) for presenting acoustic test
stimuli to a test subject within the direct sound field range of
the device. The device delivers accurate multi-level and
multi-frequency test stimuli for subjective response by the test
subject holding the device. The battery-operated device is suitable
for various hearing evaluation modes including aided (i.e., with a
hearing aid worn) and unaided conditions.
[0025] In a preferred embodiment, the invention comprises an
ultrasonic position sensor for measuring the position of the device
with respect to the head of the test subject holding the hand held
device. The distance is computed by measuring the latent period
between the transmitted ultrasonic signal and the measured
ultrasonic response reflected by the head or the ear. The acoustic
test stimuli produced by the speaker are controlled and regulated
based on the position of the device with respect to the test
individual. Thus, the accurate levels of test stimuli are presented
only upon the proper positioning of the device and irrespective of
the exact position of the device. This eliminates position and
movement-related errors commonly experienced in conventional sound
field audiometry. Furthermore, the test subject or a test operator
is automatically alerted whenever the device is incorrectly
positioned during a test.
[0026] In an embodiment of the invention, the hand-held device is
connected to an auxiliary instrument (e.g., a computer or a
microprocessor-based audiometer) for remotely controlling the
device and for registering audible responses via a response switch
provided on the invented device. In such embodiments, a test
operator can select an acoustic test stimulus from a broader range
of test stimuli. Thus, various threshold and supra-threshold tests
are presented and responses are automatically registered by the
auxiliary instrument.
[0027] In the preferred embodiment, the hand-held device is
provided with at least two keys for selecting and presenting at
least two stimulus levels. For example, the two keys may be an "S"
key for presenting Soft level sound and a "C" key for presenting
Comfortable level sound. The keys can be used by a test subject to
routinely check the proper function of an in-situ (worn in the ear)
hearing device. In another stand-alone embodiment, the hand-held
device is used as an audiometric tool to assess hearing ability and
specifically the need for a hearing aid use.
[0028] In the preferred embodiment, the device also provides
switches for selecting one of at least two signal types such as
Noise and Speech signals, and for selecting at least two frequency
bands such as Low and High frequency bands. The combination of
switches and key selections leads to a broad yet manageable range
of test options, such as Soft level High frequency Speech or
Comfortable level Low frequency Noise.
[0029] The device may be designed and configured for dual mode
configurations by first being connected to an auxiliary instrument
for performing relatively complex aided and unaided audiometric
evaluation in the presence of a hearing professional, and
subsequently as a personal evaluator for simple verification of
hearing acuity and hearing aid function.
[0030] The device may be used for either binaural or monaural
hearing evaluations. In binaural tests, the speaker of the device
is oriented facing the forehead at a distance between 30-60 cm,
depending on the individual's arm length. Although miniature and
employing a miniature audio transducer, the device can produce high
relatively intensity levels reaching 90 decibels (dB) sound
pressure level (SPL) and more when positioned close to an ear
(i.e., within few centimeters) in a monaural test mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The above and other objectives, features, aspects and
attendant advantages of the invention will become further apparent
from a consideration of the following detailed description of the
presently contemplated best mode of practicing the invention, with
reference to certain preferred embodiments and methods thereof, in
conjunction with the accompanying drawings, in which:
[0032] FIG. 1 is a view of a preferred embodiment of the invention
showing a hand held hearing evaluation device containing a speaker
and position sensor system, both oriented towards the head of the
user;
[0033] FIG. 2 is a more detailed perspective view of the hearing
evaluation device of FIG. 1 being held in hand by a user;
[0034] FIG. 3 is a view of a dual-transducer position sensor for
the embodiment of FIG. 1, having a transmitting ultrasonic
transducer and a reception ultrasonic transducer;
[0035] FIG. 4 is a view of a single-transducer position sensor
which is preferred for the embodiment of FIG. 1, having a unitary
transducer for both transmitting and reception of ultrasonic
signals;
[0036] FIG. 5 is a block diagram of the major components within the
presently preferred embodiment of the hearing evaluation
device;
[0037] FIG. 6 is a view of the hearing evaluation device correctly
positioned in range at 0.degree. degree incidence angle with
respect to the forehead of a user in a binaural test mode;
[0038] FIG. 7 is a view of the hearing evaluation device being
incorrectly positioned out of range and oriented at an unacceptable
incidence angle with respect to the forehead of a user in a
binaural test mode;
[0039] FIG. 8 is a view of the hearing evaluation device being
correctly positioned at 0.degree. degree incidence angle with
respect to an ear of a user in a monaural test mode;
[0040] FIG. 9 is a view of the hearing evaluation device also being
correctly positioned at 45.degree. degree incidence angle with
respect to an ear of a user in an alternate monaural test mode;
[0041] FIG. 10 is a view of the hearing evaluation device of the
present invention connected to an auxiliary instrument;
[0042] FIG. 11 is a view of the hearing evaluation device held by a
test operator directing the speaker at a test subject; and
[0043] FIG. 12 is an embodiment of the hearing evaluation device
incorporating a control magnet within its housing to remotely
control the function of a hearing aid worn in the ear canal.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The present invention, shown in FIGS. 1-12, provides a
personal hearing evaluation device 10 for accurately presenting
multi-level acoustic test stimuli (sounds) to an individual via an
audio transducer (i.e., speaker) 11 incorporated within the housing
of the device. The invented device 10, as shown in FIGS. 1 and 2,
is designed for holding by hand and for directing sound 13 from its
speaker 11 towards an ear 3 of a user 1 in a contactless manner but
within the direct sound field range of the speaker. In the
preferred embodiments, shown in FIGS. 1-11, the device 10 comprises
a position sensor 12 for automatically measuring the position of
the device 10 with respect to the user's head 4, or a part thereof
of interest, depending on the test mode as described below. The
device 10 also comprises keys (switches, e.g., 61 and 62, FIG. 2)
for selecting at least two levels of sound 13, presented in the
direction of an ear (monaural mode, FIGS. 8 and 9) or both ears
(binaural mode, FIGS. 6 and 7).
[0045] The position sensor 12 incorporated in the preferred
embodiment of the invented device produces incidence wave 14 (solid
arrows) which partially bounces off the head, or a part thereof
(i.e., nose, forehead, chin, ear, etc.), and becomes a reflected
wave 15 (dashed arrows) for reception by the position sensor 12.
The position sensor 12 in the preferred embodiment comprises one or
more ultrasonic transducers. FIG. 3 shows a position sensor 12
employing a pair of ultrasonic transducers. The first transducer is
a transmitter 20 for emitting incident wave 14, and second
transducer is a receiver 22, for receiving the reflected wave 15
bouncing off the head or a part thereof. The transmitter 20 and
receiver 22 transducers further employ directional filters, 21 and
23, respectively, for appropriately directing the incident wave 14
and receiving reflected wave 15. These filters improve the
reception and directionality of the position sensing process for
ensuring proper positioning of the device with the respect to the
individual.
[0046] In a preferred embodiment of the position sensor, shown in
FIG. 4, a unitary ultrasonic transducer 12 (for example,
piezoelectric transducer model ITC-9073 manufactured by
International Transducer Technology, Inc.) is employed both for
transmitting incident wave 14 and for receiving reflected wave 15.
This unitary transducer design consumes less space and thus is more
suited for the miniature battery-operated design of the hearing
evaluation device of the invention.
[0047] FIG. 5 shows a block diagram of an exemplary embodiment of
the personal hearing evaluation device 10. A controller 30 (i.e.,
microprocessor, microcontroller, etc.) is employed to perform
various computational and control processes as will be described
below. Memory 50 is employed to store program data (not shown) and
test stimulus data (51 and 52) in digital format representative of
acoustic test stimuli to be presented by the speaker 11 upon
request by the test subject 1 or a test operator 8 (FIG. 11). Test
stimulus data may be representative of speech words 51 (FIG. 5),
noise 52 and any other signal which is of audiological significance
(not shown) such as pure tone, warble tone, chirp, etc. Test
stimulus data is retrievable from memory 50 by the controller 30
for conversion into analog signal 41 by the digital to analog (D/A)
converter 40. The analog signal 41 is then delivered to a
programmable volume control 42 and then to a power amplifier 43 for
providing speaker input signal 44 to the speaker 11. Test sound 13
is finally produced by speaker 11 and directed towards the test
subject 1 positioned in the direct sound field range as shown in
FIG. 1.
[0048] The block diagram of FIG. 5 also shows position sensor 12
(an ultrasonic transducer) which transmits ultrasonic incident wave
14 and receives ultrasonic reflected wave 15 from the head or the
ear of a test subject 1 (FIG. 1). The controller 30 is also
connected to transmission circuitry 31 (labeled TRX circuitry in
FIG. 5) and reception circuitry 32 (labeled RX circuitry in FIG. 5)
for processing of signals sent and received during the process of
position sensing. The microcontroller 30 is also connected to a
switch array 60 (switches, keys, etc.) for selecting and presenting
acoustic stimuli upon the request of a test subject 1 or a test
operator 8 (FIG. 11).
[0049] A typical cycle for the position sensing process is
automatic and begins when the controller 30 receives an actuation
signal from a key (part of the switch array 60). The appropriate
pattern of initial transmission signal 33 is produced by the
controller 30 and fed into the transmission circuitry 31 which
produces an output transmission signal 35 causing the position
sensor 12 to transmit an ultrasonic incident wave 14 towards the
head or ear of the test subject. A properly positioned head or ear
with respect to the device will cause a reflected wave 15 to be
received by the position sensor 12, which produces incoming
reception signal 36. Reception circuitry 32 processes the incoming
reception signal 36 and delivers a filtered reception signal 37 to
controller 30. The latency period--the time between the onset of
signal transmission and reception--is employed by the controller 30
to compute the position of head or ear with respect to the device
10. The above mentioned process is typically performed in repeated
bursts or packets of sensing signals, according to an appropriate
detection algorithm, for determining the correct position of the
device in the presence of possible noise and interference.
[0050] Upon proper positioning of the device by the position sensor
system (in FIG. 5 comprising ultrasonic transducer position sensor
12, transmission circuitry 31, reception circuitry 32 and
microcontroller 30), the device 10 delivers an acoustic test
stimuli via speaker 11 to the test subject 1. It will be
understood, of course, that although the incident wave 14 delivered
by position sensor 12 and the test stimulus delivered via speaker
11 to the test subject appear to be directed in opposite directions
in the block diagram of FIG. 5, this is simply for the sake of
convenience of block diagrammatic representation and they are
actually delivered in the same general direction as indicated in
FIGS. 1 and 2. The automatic position sensing process is relatively
rapid and typically occurs within 100 milliseconds (ms) after
pressing a stimulus request key. Therefore, the onset of a test
stimulus is essentially perceived "instantaneously" by a test
subject.
[0051] However, if the positioning of the head is determined
improper by the position sensor system (i.e., out of range,
improper orientation, reverberant environment, etc.), the device
presents the appropriate alarm indicator to the user. FIG. 2 for
example shows an alarm light indicator 71 in the form of an LED
(light emitting diode). Alternatively, a LCD (liquid crystal
display) or even distinct audible sounds (i.e., buzzer-like) may be
employed to alert the user of an improper positioning or function
of the invented device. Display elements are collectively shown as
LED/Display 70 in FIG. 5.
[0052] The device in the embodiment shown in FIG. 5 also
incorporates a microphone 16 for sensing the ambient background
noise 17 and ensuring acceptable noise levels prior to delivering a
test stimulus. For example, the onset of a test stimulus may be
automatically delayed or canceled if the ambient noise level was
measured to exceed the level of an intended test stimulus. In
another example, the level of intended test stimulus may be
automatically increased to ensure acceptable signal to noise (SIR)
ratio. The microphone may also be used for self-testing or
auto-calibration of the device by sensing a calibration signal (not
shown) delivered by the speaker 11 and comparing its measured
characteristics to a predetermined pattern stored in memory 50. The
microphone signal 39 from the microphone 16 is amplified by
microphone signal amplifier 38 and delivered to controller 30 for
digital sensing and computation. An analog to digital converter
(not shown) is preferably employed, within the microcontroller 30
or as a separate component within the device, in order to convert
microphone signals and various analog signals within the device
into a digital format for interpretation and computation by the
controller 30. A battery 27 is provided to power the portable
hearing evaluation device 10 of the present invention.
[0053] FIG. 6 shows an example of a binaural test mode of the
hearing evaluator device 10 positioned within proper range 60 and
orientation (0.degree. degree incidence angle) with respect to the
user's forehead 4. Sound, 13 and 13', from speaker 11 is directed
at right 3 and left 3' ears, respectively. A sufficient portion of
incidence wave 14 transmitted from position sensor 12 is reflected
back (reflected wave '15) to the position sensor 12 causing
reception signal 37 (FIG. 5) of sufficient strength and latency for
proper detection by the position sensing system. The distance of
the device with respect to the forehead is preferably in the range
of 30-60 cm to accommodate the arm length range of individuals
holding the device as shown in FIGS. 1 and 2.
[0054] FIG. 7 shows an example of a binaural test mode with device
10 being incorrectly positioned outside the proper range 60 and
also being incorrectly oriented with respect to the forehead 4 of
the user 1. Since the incident angle 0 (61) is much greater than
0.degree. degree, the incident wave is minimally reflected, if at
all. However, even if a fringe incident wave 14' is reflected
causing a fringe reflected wave 15', the reception signal 37 is
insufficiently weak as determined by the position sensor
system.
[0055] In the binaural test mode, shown in FIGS. 6 (correct) and 7
(incorrect), both ears are typically involved in the hearing
evaluation process. However, if only a single ear is to be tested
in this mode, the other ear must be excluded by an appropriate
method such as by occluding the non-test ear or by turning off a
hearing aid worn in the non-test ear.
[0056] FIG. 8 shows a preferred method for monaural hearing
evaluation. The invented device 10 is placed within exceptional
proximity to a single test ear 3 (right). In this monaural test
mode, the device is placed within a 2-10 cm range from the ear and
oriented at incidence range of 0.degree.-45.degree. degrees. FIG. 8
shows device placement at 0.degree. degree incidence with respect
to right ear 3. FIG. 9 shows device placement at 45.degree. degrees
incidence with respect to a left ear 3'.
[0057] FIG. 2 shows a perspective view of an exemplary embodiment
of the hearing evaluation device 10 being held by hand 5 of a test
subject (1 in FIG. 1). The device 10 comprises a first key 61
configured for pressing by the thumb 6 and a second key 62
configured for pressing by the index finger 7. The speaker 11 is
oriented towards one or both ears as shown in FIGS. 6-9 and
described above. Light Emitting Diodes (LED), 71 and 72, are
employed to provide visual indications to the test subject 1. For
example, an alarm LED 71 (typically a red light) is provided to
indicate incorrect positioning of the device. LED 72 (typically a
green light) may be used to indicate valid "OK" operation or
charged battery. A directional filter 21 is fitted over the
position sensor 12 to improve the directionality of incident wave
14, reflected wave 15, or both. A speaker cover 45 with holes 46,
or an acoustically transparent structure (not shown), are provided
to protect the speaker 11 within while allowing test sound 13 to
pass through towards the test subject.
[0058] FIG. 2 also shows a first switch 25 (two-position switch)
for selecting one of two signal types; speech (marked SP) or
narrow-band-noise (marked NBN). A second switch 26 (three-position
switch) provides selection of one of three frequency bands; low,
medium or high (labeled LF, MF and HF, respectively). Keys, 61 and
62, are employed to select at least two levels of sounds. In the
preferred embodiment, these two keys present soft and comfortable
sound levels, both with respect to normal hearing individuals. Soft
sound key 62, for example, (marked "S") preferably presents a fixed
level sound in the range of 20 to 40 dB HL (hearing level).
Comfortable sound key 61, for example, (marked "C") preferably
presents a fixed level sound in the range of 45 to 60 dB HL.
[0059] The exemplary key and switch configuration of the device 10
in FIG. 2 leads to a combination of 12 individual test stimuli
(2keys.times.2 positions.times.3 positions) for performing various
hearing evaluation tests. The accuracy of each test stimuli
presented is ensured and regulated by the position sensor system
incorporated within as described above. For example, if the
speaker-head distance is measured (automatically) to be at 50 cm
(i.e., binaural test mode), the speaker input signal 44 (FIG. 5) is
then automatically reduced relative to a condition where the
speaker-ear distance is at 5 cm (i.e., monaural test mode). This
automatic adjustment (auto-calibration) is necessary in order to
produce an equal perception of loudness at the ear, irrespective of
the test mode or the exact position of the speaker 11.
[0060] In addition to the automatic level adjustment affecting the
speaker input signal, the frequency characteristics of the test
sound may also be manipulated in order to minimize inaccuracies
associated with frequency-dependent stimulus. In pure tone test
sounds, for example, it may be desirable to slightly shift the test
frequency in order to minimize the affects of standing waves. A
slight shift in the frequency is considered acceptable in
audiological standards for most audiometric evaluations. For
example, .+-.1% and .+-.3% frequency variation is permissible for
type 1 and type 4 audiometers, respectively, according to ANSI
S3.6, 1996.
[0061] The types of test signals possible with the present
invention are not limited to speech, pure tones or
narrow-band-noise. Virtually any signal of audiological
significance may be reproduced from a digital recording, or
synthesized, by the microcontroller for the presentation to the
test subject. Other possible signal types include warbled tones,
white noise, chirp (sine-wave composition), speech noise and other
frequency weighted signals.
[0062] The hearing evaluator of the present invention, although
miniature and employing a miniature audio transducer (speaker) 11,
can produce sound at significant intensity levels when positioned
within close proximity to a test ear as shown in FIGS. 8 and 9. In
this monaural test mode, the intensity levels of test stimuli at
the ear can reach 90 dB-SPL (sound pressure level) or more while
consuming little energy available from standard batteries. For
example, a 98.3 DB-SPL tone at 4000 Hz was produced at the ear from
a miniature high fidelity speaker (model 4D06C manufactured by
Panasonic) when positioned approximately 5 cm from an individual's
ear (monaural test mode FIG. 8). The speaker input signal voltage
to produce the 98.3 dB at 5 cm was measured at 0.7 Vrms. The power
into the speaker measured at about 0.05 watt, which is readily
available from standard batteries. Loud level sounds at 90 dB-SPL
are particularly useful in assessing the aided hearing function of
an individual during the fitting process to ensure comfortable
hearing when the hearing aid is subjected to loud sounds. If found
too loud by the aided test subject, the maximum output of the
hearing aid must be reduced to a more acceptable level.
[0063] The same speaker input signal level (0.7 Vrms) produced only
82.5 dB-SPL at the ear when the speaker was positioned at 40 cm.
Obviously, by scaling down the speaker input signal, soft and even
threshold level sounds can be readily produced at virtually any
distance within the preferred usable range of 2 to 60 cm. The above
sound pressure level measurements at the ear were taken by
probe-tube microphone system (model ER-7C, manufactured by Etymotic
Research).
[0064] The personal hearing evaluator device 10 can be used by a
test subject 1 to conduct a self-administered screening evaluation
(pass/fail test) using the keys provided on the device.
[0065] The device in the above-described preferred and alternate
embodiments can also be used in a professional setup during the
fitting process of a hearing aid. For example, in the unaided
condition and prior to hearing aid selection, the threshold of
hearing of an individual (test subject) is determined at various
audiometric frequencies. Later on, the hearing evaluation is
performed while a hearing aid is in situ (worn in the ear or the
ear canal). In this aided condition, adjustments to the in-situ
hearing aid are made while the test subject responds to the sound
field stimuli produced by the hand-held device of the present
invention. For example, soft level gain, compression ratio, maximum
output, frequency response, attack time and any other parameter of
a hearing aid, may be adjusted based on the test sounds produced
from the speaker of the hand-held device. Following the fitting
process, the test subject can use the hearing evaluation device 10
as a personal hearing evaluator. For example the acuity of the
aided hearing can be checked regularly by the user at home by
pressing the soft level key (62 in FIG. 2) to present soft level
sounds (audible by normal hearing individuals). This is important
because hearing aids tend to gradually deteriorate with time due to
moisture or earwax contamination. A regular check-up by the hearing
evaluation device of the invention should detect possible changes
in either the hearing aid or the hearing ability of the user.
[0066] In the above-described embodiments, the hand-held hearing
evaluation device is described in stand-alone configurations for
use in unaided or aided conditions. FIG. 10 shows an alternate
embodiment of the device 10 connected to an auxiliary instrument 80
(shown as a computer or computer-based instrument). The elongated
hand-held device 10 is provided with an interface port 28 (also
shown in FIGS. 2 and 5) for connecting to auxiliary instrument 80
via the connection cable 81 and its electrical plug 82 inserted
into interface port 28 of the device 10. The auxiliary instrument
80 is used by a test operator to control the device 10 by sending
the appropriate control commands to the controller 30 (FIG. 5) of
the device via auxiliary interface circuitry 48 (FIG. 5). This
auxiliary control mode available by the present invention allows a
test operator (other than the test subject holding the device 10)
to remotely control the function of the device 10. One advantage of
this mode is to allow the operator to select a test stimulus from a
broader range than possible with the device in its stand-alone
configuration (having relatively a limited number of key and switch
selection). The remote control interface mode is useful, for
example, in performing a more comprehensive hearing evaluation such
as for conducting a complete audiogram test involving 6 or more
frequencies. In the remote control mode by an auxiliary instrument
80, a key (such as key 61 or key 62) within the device 10 can be
used as a response key to register responses of the test subject
and relay such registration to auxiliary instrument 80 when the
test subject hears and presses the response key.
[0067] The auxiliary instrument 80, in conjunction with a response
key on the device, can be used to automate the presentation of a
hearing test according to procedures and protocols known in the
field of automated audiometry. Furthermore, the auxiliary
instrument 80 may be used to program the connected device 10 to
perform specific test or function according to the needs of the
individual test subject. The auxiliary instrument 80 may be a
computer as shown, a microprocessor-based audiometer instrument
(not shown), or any other suitable control instrument. The
connection between the auxiliary instrument 80 and the device 10
may be via a direct wire as shown in FIG. 10, or via a wireless
connection (not shown) as widely known in the field of wireless
control and communications.
[0068] The auxiliary instrument mode is ideally suited during the
initial fitting evaluation at the site of the hearing aid
dispensing professional. For example, a test operator (audiologist,
doctor, nurse, etc.) can perform various unaided and aided
evaluation on a test subject holding the device by hand. Once the
hearing aid fitting process is completed, the hand-held device 10
is then disconnected from the auxiliary instrument 80 and offered
to the test subject as a personal evaluator. Similarly, the
personal evaluator device 10 can be used to regularly verify the
proper function of an in-situ hearing device. The personal
evaluator device 10 comprises a battery 27 for powering the device
in its stand-alone mode after being disconnected from the auxiliary
instrument 80.
[0069] The auxiliary instrument mode is also suited for remotely
administering a hearing test when the subject is remotely present
and the device is connected to the appropriate network. For
example, a hand-held device 10 can be directly connected to a
computer which is also connected to a remote computer (auxiliary
instrument) via the Internet. This way, a hearing professional can
remotely administer a test to a test subject, present at home for
example. In this case, the test subject simply connects the hearing
evaluation device 10 to a computer port (not shown) of a personal
computer connected via the Internet to the computer of the hearing
professional. Other remote interface methods are possible and
conceivable as will become obvious to those skilled in the art of
computers, communications and networking.
[0070] The invented device 10 is highly portable and configured for
easy transport and convenient hand-held operation as described in
the above embodiments. For example, the device in FIG. 2 is shown
resembling a hand-held stopwatch or a garage-door opener. In FIG.
10 the device 10 is shown resembling a pen. Other designs, well
within the scope of this invention, include wristwatch 95 (FIG. 13)
and other configurations, which will become obvious to those
skilled in the art of miniature personal instrument design.
[0071] The invented device 10, although most suitable for holding
by a test subject who orients the speaker towards his or her own
ears, it may be desirable in certain conditions for a test operator
(a hearing professional, parent, spouse, etc.) to hold the device
10 and assist in conducting a hearing test. This may be necessary
for testing young children, persons with poor dexterity, and other
difficult to test individuals. FIG. 11 shows a test operator 8
holding the hearing evaluation device 10. Similarly, the test sound
13 and the incident wave 14 of the position sensor 12 are directed
towards the head 3 of the test subject 1 to properly deliver
acoustic test stimuli to one or both ears of the test subject
1.
[0072] The personal hearing evaluator may incorporate wireless
remote control means for remotely controlling or programming a
hearing aid. For example, hearing aid volume can be remotely
adjusted, or the power may be remotely turned on or off. Wireless
control means are widely known in the field of hearing aids and
include ultrasonic, electromagnetic, sonic, magnetic and infrared
signals. In a preferred embodiment shown in FIG. 12, the hearing
evaluator device 10 comprises a magnet 18 having a magnetic field
19 which remotely, but within close proximity, controls a hearing
aid 90 positioned in the ear canal 7. The magnetic field 19 may be
reversed in its direction (not shown) simply by flipping the device
and thus reversing the polarity of the magnet 18 within. The
details of such magnetic control operation are disclosed in a
pending patent application Ser. No. 09/181,533 of the same
inventor, filed Oct. 28, 1999 and incorporated herein by reference.
The magnet typically employed within a speaker 11 transducer may be
relied on for such remote control application thus eliminating the
need for an additional magnet.
[0073] The position sensor system in the preferred embodiments,
described above, employ ultrasonic transconduction for sending and
receiving ultrasonic waves. However, other contactless position
sensing means are possible and may be equally suitable as known by
those skilled in the art of proximity and position sensing. For
example by employing optical transducers (i.e., infrared LED) in
conjunction with appropriate directional optical filters. In
another example, a sonic wave produced by the speaker 11 may be
utilized for position sensing.
[0074] Although a presently contemplated best mode of practicing
the invention has been described herein with reference to certain
presently preferred and alternate embodiments and methods of use,
it will be recognized by those skilled in the art to which the
invention pertains from a consideration of the foregoing
description, that variations and modifications of these exemplary
embodiments and methods 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.
* * * * *