JP3946131B2 - Automatic amplification characteristic adjustment device for hearing aids - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a device for adjusting an automatic amplification characteristic of a hearing aid, and more particularly, before the wearer wears the hearing aid, the wearer needs for each characteristic of the hearing aid that is different for each model. The present invention relates to an automatic amplification characteristic adjustment device for a hearing aid that can be set and adjusted in accordance with the characteristic.
[0002]
[Prior art]
When using a hearing aid, since the size of the sound output required by each wearer varies, the amplification degree (amplifier) of the amplification unit (amplifier) of the hearing aid is set so that the sound output required by the wearer is obtained. Fitting (adapting) work to adjust (gain).
[0003]
In this fitting, the hearing aid's amplification characteristics, maximum output level, and other characteristics are set based on the hearing diagram of the pure tone audiogram obtained from the hearing test of the wearer. It is adjusted after wearing.
[0004]
In hearing aid fittings that have been widely performed in the past, adjustments are made with reference to a hearing level (HTL: minimum audible threshold level) that is the minimum sound pressure level that can be heard by a device equipped with a computer.
[0005]
In this conventional hearing aid fitting device, the wearer (subject) listens to the sound generated from the speaker controlled by the sound source unit via the hearing aid, and a new adjustment value is obtained based on the evaluation of the wearer. (For example, refer to Patent Document 1).
[0006]
In the device, multiple standard gain curves are prepared in which the gain for each frequency is determined from the audiogram using the half-gain rule or the hearing instrument manufacturer's original rules. Select an amplification curve for the wearer based on the feeling and experience, and increase or decrease the selected amplification curve uniformly with respect to the hearing level (HTL) of the wearer, or one to several frequencies. For example, the amplification degree of the hearing aid is set by increasing or decreasing the amplification degree and increasing or decreasing the amplification degree of the surrounding frequency range to match it.
[0007]
Then, the set hearing aid is worn for a period during which the wearer wears the hearing aid, and readjustment is performed to change the amplification characteristic data again based on the judgment of the wearer. By repeating this readjustment, the satisfaction of the wearer is sought.
[0008]
[Patent Document 1]
JP 2001-128295 A (Page 3, FIG. 1)
[0009]
[Problems to be solved by the invention]
However, in the adjustment performed for the wearer while wearing the hearing aid, the amplification level of the hearing aid is adjusted and the maximum output is set based on the hearing of the wearer. It is almost impossible to adjust the amplification at frequency intervals, and this adjustment usually ends at one or several points. In addition, adjusting the maximum output sound pressure level of a hearing aid while listening to sound generated by a speaker, etc. is not only painful for the wearer, but also has limitations in equipment and adjustment time. Is difficult to implement.
[0010]
Further, in fitting of conventional hearing aids, a comfort level (MCL: comfort threshold level) that is a comfortable sound pressure level, which is an index of ease of hearing, and a discomfort level that is a sound pressure level that feels so loud that you do not want to listen to it. Since the target amplification curve is set based on the hearing level instead of (UCL: discomfort threshold level), the comfort level and discomfort level that are required for hearing aid adjustment remain unclear, There is a problem that it is difficult to adjust to the comfort that can satisfy the wearer because the adjustment is performed by the trial listening of the wearer.
[0011]
Actually, the amplification characteristic of the hearing aid has a different amplification characteristic for each hearing aid model, and does not necessarily have the amplification characteristic of the standard amplification curve. In the average level adjustment and amplification adjustment for several frequencies, the amplification characteristics of different hearing aids for each hearing aid model are ignored, and the deviation (individual difference) for each product is not adjusted. It is adjusted on the basis of the standard amplification characteristic.
[0012]
Therefore, it is not possible to set the amplification factor in each frequency band in accordance with the target amplification curve in all frequency bands to be adjusted. It will be insufficient.
[0013]
In other words, in the display on the screen of the conventional fitting device, the characteristic graph of the hearing aid displayed on the display of a computer or the like converts the energy of the amplifier elements programmed to obtain the output set by the individual hearing aid, and converts the energy. Amplification curve adjusted based on the standard amplification characteristics that do not contribute to variations in microphones and earphones is shown, so it is judged that the adjustment has been made properly, but the actual hearing aid after making this adjustment When looking at the amplification curve obtained by measuring the output sound for each frequency, there are many portions having a large deviation from the target amplification curve.
[0014]
The present invention requires a sound obtained by amplifying the measurement sound generated by the measurement sound generation unit with a hearing aid using a coupler, and measuring the comfort level and the discomfort level in the voice band over the entire frequency band to be adjusted. Provided is an automatic amplification characteristic adjustment device for a hearing aid capable of automatically calculating a comfort level and an uncomfortable level and automatically adjusting an amplification degree for each frequency band of the hearing aid so as to generate an output of a target sound pressure level. There is.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, an automatic amplification characteristic adjusting device for a hearing aid according to the present invention includes a measurement sound generator, a coupler for receiving a sound obtained by amplifying the measurement sound generated by the measurement sound generator, and the coupler. A sound pressure detection unit for detecting the output sound level of the input sound, a comparison determination unit for comparing the measurement data detected by the sound pressure detection unit with the target data, and the correction of the hearing aid from the comparison data in the comparison determination unit And a control unit for inputting the correction data generated by the correction data generation unit to the hearing aid, and the hearing aid of the hearing aid is determined from the measurement results of the comfort level and the discomfort level in the voice band of the deaf ear. By calculating the amplification characteristics, the output of the hearing aid that is input to the microphone in the coupler with respect to the measurement sound of the wide frequency band generated by the measurement sound generator is An automatic amplification characteristic adjustment device of the hearing aid, characterized in that for automatically adjusting the amplification degree of the hearing aid so that the target output.
[0016]
According to this device, the output of the hearing aid that is input to the microphone in the coupler with respect to the measurement sound of the wide frequency band generated by the measurement sound generator over the entire range of the wide frequency band to be adjusted is a predetermined frequency. The degree of amplification of the hearing aid is adjusted so that it becomes the target output every time, and at the time of this adjustment, the wearer does not intervene, and the hearing aid in the voice band is determined from the result of measuring the comfort level and the uncomfortable level in the voice band of the deaf ear. Therefore, it is possible to easily adjust the maximum output sound pressure level of the hearing aid without taking the wearer's time.
[0017]
In addition, since the frequency base can be adjusted automatically for many frequencies instead of an average adjustment or one or several adjustments, it is sufficient for living environment sounds that have a wide range of sounds. Adjustment can be performed, and the characteristics of the hearing aid can be adjusted to the target value regardless of variations in the amplification characteristics of the hearing aid that are different for each hearing aid model and individual differences among the individual hearing aids.
[0018]
Further, in the above-described automatic amplification characteristic adjustment device for a hearing aid, the correction data creation unit is configured to bring the hearing aid output to a comfortable level based on the result of measuring the output of the hearing aid for the measurement sound generated by the measurement sound generation unit. By creating correction data for correcting the amplification level of the hearing aid so as to achieve the target output set for the hearing aid, the amplification curve of the hearing aid can be adjusted so that the output from the hearing aid is at a comfortable level. Therefore, in order to adjust at a comfortable level that is a sound pressure level that can be heard comfortably as an index of ease of hearing, it is possible to adjust to a level of comfort that can satisfy the wearer.
[0019]
Then, the correction data generation unit generates correction data for correcting the amplification degree of the hearing aid so that the output of the hearing aid with respect to the measurement sound within the range of 50 dBSPL to 70 dBSPL generated by the measurement sound generation unit becomes a comfortable level. By doing so, it becomes possible to perform practical adjustment efficiently.
[0020]
Furthermore, in the automatic amplification characteristic adjusting device of the hearing aid, the maximum output sound pressure level of the hearing aid is determined based on a result of the correction data creation unit measuring the output of the hearing aid with respect to the measurement sound generated by the measurement sound generation unit. Amplification of the maximum output of the hearing aid so that the maximum output of the sound from the hearing aid does not exceed the uncomfortable level by creating correction data to correct the target maximum output sound pressure level set for the unpleasant level The degree curve can be adjusted.
[0021]
The correction data generation unit corrects the maximum output sound pressure level of the hearing aid so that the output of the hearing aid for the measurement sound within the range of 85 dBSPL to 95 dBSPL generated by the measurement sound generation unit does not exceed the uncomfortable level. By creating business data, efficient and practical adjustments can be made.
[0022]
Therefore, according to the automatic amplification characteristic adjustment device for a hearing aid having the above-described configuration, the amplification characteristic of the hearing aid in the sound band is calculated from the result of measuring the comfort level and the discomfort level in the sound band of the deaf ear using an insert horn or the like. The amplification characteristics can be automatically adjusted.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Next, an automatic amplification characteristic adjusting device for a hearing aid according to an embodiment of the present invention will be described with reference to the drawings.
[0024]
As shown in FIG. 1, an automatic amplification characteristic adjusting device 10 for a hearing aid according to an embodiment of the present invention includes a measurement sound generator 11, a coupler (artificial ear) 12, a sound pressure detector 13, a target data generator 21, The comparison determination unit 22, the correction data creation unit 23, the control unit 24, the characteristic output unit 25, and the image display unit 26 are configured.
[0025]
The measurement sound generator 11 is composed of a sound source capable of generating a measurement sound such as a pure tone or a narrow band noise, and the coupler 12 is suitable for measuring a cavity having a predetermined shape and volume and a sound in the cavity. And a sound obtained by amplifying the measurement sound generated by the measurement sound generator 11 by the hearing aid 30. The sound pressure level of the sound input by the microphone of the coupler 12 is detected for each frequency (or for each frequency band) by the sound pressure detection unit 13, and the detected output sound level (sound pressure level) is compared and determined by the determination unit 22. Output to.
[0026]
Then, the target data creating unit 21 stores the hearing test data of the wearer obtained by the test of the hearing test device 40, and sets target data as an adjustment target of the hearing aid 30 from the test data. Store the setting data.
[0027]
The target data includes optimum output data (or optimum amplification degree data) corresponding to the comfort level and maximum corresponding to the discomfort level, which are set for a predetermined number of frequencies that can represent the entire frequency band to be adjusted. Output data (or maximum sound amplification degree data). In some cases, the target data is an amplification degree curve (response) in which the discrete data is represented by a frequency-based curve (function).
[0028]
The comparison determination unit 22 compares the measurement data (output data) detected by the sound pressure detection unit 13 with the target data, and determines whether or not the comparison result satisfies the standard, that is, the deviation between the measurement data and the target data. Is within a predetermined range, and thereby, it is determined whether the adjustment and correction are completed.
[0029]
The correction data creation unit 23 shown in FIG. 1 creates correction data at the frequency from the measurement data and comparison data at a predetermined frequency in order to correct the output of the hearing aid 30. As shown, the adjustment data and the correction data are output to the adjustment unit 34 of the hearing aid 30. Further, the characteristic output unit 25 in FIG. 1 outputs the target data of the characteristic set as a target and the actually measured measurement data to the image display unit 26 for display.
[0030]
The hearing aid 30 is a program hearing aid or the like having an IC chip that can adjust and correct the amplification degree (gain: gain) by writing amplification characteristics into the IC chip using a computer or a dedicated input device. As shown in FIG. 2, the input unit 31 includes a microphone, an amplification unit (amplifier) 32, an output unit 33 including an earphone, and an adjustment unit (adjustment device) 34.
[0031]
The amplifying unit 32 is provided not only with an amplifying function but also with an output limiting function, and restricts a sound that is not too loud to the ear even when a loud sound is input. The adjustment unit 34 is configured to have not only an amplification degree adjustment function but also an output upper limit adjustment function.
[0032]
Then, based on the adjustment data and the correction data input from the control unit 24 of the automatic amplification characteristic adjustment apparatus 10 to the adjustment unit 34, the amplification degree of the amplification unit 32 is adjusted and corrected, and the sound signal input from the input unit 31 Is amplified by the amplifying unit 32, and the amplified sound is output from the output unit 33.
[0033]
Next, adjustment of the hearing aid 30 using the hearing aid automatic amplification characteristic adjusting device 10 will be described. This adjustment is performed according to the flow illustrated in FIGS.
[0034]
As shown in FIG. 3, this adjustment includes a test for the ear in step S10, creation of target data in step S20, automatic adjustment of hearing aid characteristics in step S30, and readjustment after wearing in step S40. The automatic amplification characteristic adjusting apparatus 10 according to the invention is used in the creation of target data in step S20 and the automatic amplification characteristic adjustment of the hearing aid in step S30, and exhibits its effect.
[0035]
As shown in FIG. 4, in the test relating to the ear in step S10, as shown in FIG. 4, a general test such as a test of the external auditory canal and a test of the eardrum, a pure tone hearing test, a hearing test using band noise, a speech test, etc. The hearing test using the hearing test apparatus 40 (FIG. 1) is performed. The hearing test device 40 can select a pure tone, a continuous or intermittent sound of band noise, a microphone sound, or an externally input sound source, and can be used as a test sound.
[0036]
In the pure tone hearing test, the hearing level (HTL: minimum audible range level) is obtained, and in the hearing test using band noise, a guideline for determining the maximum output sound pressure at the time of fitting in the discomfort level test (UCL test) is obtained. In the comfort level test (MCL test), find out how loud the sound is best. Moreover, in the speech sound hearing test, the listening ability is actually tested using human words. By these tests, data of hearing level (HTL), comfort level (MCL), and discomfort level (UCL) are obtained.
[0037]
In step S13, the hearing test data is output from the hearing test device 40 to the target data creation unit 21 of the automatic amplification characteristic adjusting device 10 as shown in FIG.
[0038]
As shown in FIG. 5, the next step S20 includes hearing test data in step S21, setting of target data in step S22, and storage of target data in step S23.
[0039]
In this step S <b> 21, the wearer's hearing test data obtained by the hearing test apparatus 40 is input to the target data creation unit 21 of the automatic amplification characteristic adjuster 10. This input may be input from the hearing test apparatus 40 online or offline via a storage medium such as a flexible disk, or may be performed by keyboard input. Note that step S21 is executed simultaneously with step S13. In other words, the same step is expressed by changing the way of viewing.
[0040]
In step S22, when the sound input from the outside is amplified by the hearing aid 30 based on the data of the comfort level of the wearer, the sound output from the hearing aid 30 is the comfort level with respect to the ear of the wearer, that is, Amplification data is created so that the sound pressure level is just as easy to hear.
[0041]
Further, in step S22, the maximum output is limited based on the discomfort level data of the wearer so that the sound pressure level of the sound generated from the hearing aid 30 does not exceed the discomfort level that is felt so loud that it does not want to be heard. Create maximum output data.
[0042]
The creation of these data is usually performed in a sound range of 250 Hz to 4 kHz, and further adjustment data of the hearing aid 30 is created based on these target data and maximum output data. These target data and adjustment data are discrete data at a predetermined frequency, curves (functions) based on the frequency, and map data.
[0043]
In step S23, the target data such as the amplification data and the maximum output data created in step S22 and the adjustment data based on these target data are stored in the target data creating unit 21.
[0044]
When the creation of the target data is completed, automatic amplification characteristic adjustment by the automatic amplification characteristic adjustment device 10 of the hearing aid is performed in the next step S30.
[0045]
In the loop of steps S32 to S38 shown in FIG. 6, measurement data is detected, compared, and corrected data is created for target data such as amplification data and maximum output data at the frequency (or frequency band) to be adjusted. The output is amplified, the output amplified by the hearing aid 30 is fed back to the measurement sound generated by the measurement sound generator 11, the amplification degree and the maximum output of the hearing aid 30 are adjusted, and the output and characteristics (amplification) of the hearing aid 30 are adjusted. (Characteristic) is a value close to target data such as target output.
[0046]
More specifically, as shown in FIG. 6, in step S31, the hearing aid 30 is set on the coupler 12 of the automatic amplification characteristic adjusting device 10, the switch of the hearing aid 30 is turned on, and key input and switch ON operations on the keyboard are performed. When the start signal for the automatic amplification characteristic adjustment is input by the automatic amplification characteristic adjustment, the automatic amplification characteristic adjustment starts. As shown in FIGS. 1 and 2, the adjustment data of the target data creation unit 21 is adjusted by the control unit 24 by the adjustment unit of the hearing aid 30. 34, and the amplifying unit 32 is adjusted.
[0047]
In the next step S32, the adjustment data stored in the target data creation unit 21 is output to the adjustment unit 34 of the hearing aid 30. In step S33, the target data stored in the target data creation unit 21 is output to the characteristic output unit 25. The target data such as the target optimum output, the upper limit output, and the target optimum amplification degree are shown on the image display unit 26.
[0048]
On the other hand, in step S34, the measurement sound generator 11 sequentially generates the measurement sound and receives the sound from the hearing aid 30 by the coupler 12, and in the next step S35, the sound pressure detector 13 outputs the output sound level, That is, the output sound level (sound pressure level) of the sound output from the hearing aid 30 and received by the coupler 12 is obtained.
[0049]
When adjusting the target optimum output, the measurement sound generator 11 generates a pure sound within a range of 50 dBSPL to 70 dBSPL, preferably 65 dBSPL, within a range of 200 Hz to 8 kHz. Further, when adjusting the maximum output, that is, the maximum output sound pressure (MPO: Maximum Power Output), a pure tone within the range of 85 dBSPL to 95 dBSPL, preferably 90 dBSPL, within the range of 200 Hz to 8 kHz is generated.
[0050]
If the deviation between the measurement data and the target data at each frequency is not within the predetermined determination value in the comparison of the characteristic data in the next step S36, the correction data creating unit 23 determines that the deviation is a predetermined determination value in step S37. Correction data is generated for the frequency not included in the frequency, and is output to the control unit 24 in step S38. Then, the process returns to step S32.
[0051]
In step S31, the correction data is output from the control unit 24 to the adjustment unit 34 of the hearing aid 30, and characteristics such as the amplification degree and the maximum output of the amplification unit 32 are automatically adjusted by the adjustment unit 34 on the hearing aid 30 side. .
[0052]
Then, Steps S32 to S36 and Steps S37 and S38 are repeated. Finally, the characteristics of the hearing aid 30 are corrected to match the target data, and the measurement data and target at each frequency are determined in the data comparison determination in Step S36. Since all deviations from the data are within the predetermined determination value, when this state is reached, the automatic adjustment is terminated and the process proceeds to the output of the measurement characteristic diagram in step S39. In the output of the measurement characteristic diagram, the characteristic output unit 25 displays the measurement data on the image display unit 26 and compares it with the target data of the target data. Thereby, the automatic amplification characteristic adjustment of the hearing aid in step 30 is completed.
[0053]
At the end of this automatic amplification characteristic adjustment, “end of automatic amplification characteristic adjustment” is notified by lamp lighting or screen display, or by voice notification. Upon receiving this notification, the operator removes the hearing aid 30 and ends the automatic amplification characteristic adjustment work for the hearing aid 30.
[0054]
This automatic amplification characteristic adjustment may be performed for each frequency. After adjusting the characteristic of a predetermined frequency to the target data, it is manually repeated to move to the next frequency, and finally all adjustments to be adjusted are made. The adjustment and correction of the characteristics may be completed at the frequency.
[0055]
When the automatic amplification characteristic adjustment is completed, readjustment is performed after wearing in the next step S40. In this readjustment, the comfort level is confirmed and the discomfort level is confirmed based on the hearing of the wearer who actually wears the hearing aid 30, and if there is a malfunction, the characteristics of the hearing aid 30 are readjusted. .
[0056]
In this readjustment, the wearer wears the hearing aid 30 in step S41 of FIG. 7, and in step S42, the test sound from the test sound source in the hearing test apparatus 40, the hearing measurement room, or the like, Ask them to determine if the sound they hear in the environment they encounter is comfortable or uncomfortable.
[0057]
For example, the wearing range value in the field is 45 dBSPL, whether or not normal speech can be heard, a test of word intelligibility is tested, and a 90 dBPL band is used to confirm the discomfort level. Listen to noise, intermittent sounds, and intersections. Furthermore, since it is important that the voice is heard comfortably, this confirmation is also made.
[0058]
In step S43, it is determined whether readjustment is necessary. If readjustment is necessary, new adjustment data is input to the adjustment unit 34 of the hearing aid 30 in step S44, and readjustment is performed. Return. In this readjustment, readjustment data is obtained by manual input by an operator by a manual control (manual adjustment) unit 50 constituted by a personal computer (PC) or the like, and the hearing aid 30 is set in the automatic amplification characteristic adjusting device 10. The readjustment data is input to the control unit 24 of the automatic amplification characteristic adjusting device 10 and readjusted via the control unit 24.
[0059]
If readjustment is unnecessary in step S43, the process goes to the end of step S45, and the readjustment is finished.
[0060]
Note that such final readjustment falls within ± 5 dB with respect to the setting made in the automatic amplification characteristic adjustment.
[0061]
According to the automatic amplification characteristic adjusting apparatus 10 as described above, in fitting the hearing aid 30, the individual characteristics of the hearing aid 30 can be automatically adjusted at the frequency to be adjusted so as to match the target data for each frequency.
[0062]
Further, both the amplification data and the maximum output data can be adjusted as target data. In addition, whether or not the set characteristic is appropriate can be confirmed on the spot by the screen display unit 26.
[0063]
Therefore, the readjustment after wearing in step S40 can be performed with the hearing aid 30 adjusted and corrected to a beautiful curve characteristic, so that the readjustment can be performed in a very short time and the burden on the wearer is reduced. Can do.
[0064]
【The invention's effect】
As described above, according to the automatic amplification characteristic adjustment device for a hearing aid according to the present invention, from the data of the test result of the comfort level and the discomfort level in the sound band of the hearing-impaired ear, over the entire range of the wide frequency band to be adjusted, Automatically adjusts the degree of amplification of the hearing aid so that the output of the hearing aid input to the microphone in the coupler becomes the target output for each predetermined frequency for the wide frequency band measurement sound generated by the measurement sound generator be able to.
[0065]
In this automatic adjustment, since it is not necessary for the wearer or the operator to intervene, it is possible to easily adjust the hearing aid without taking the time of both.
[0066]
In addition, since the frequency base can be adjusted automatically for many frequencies instead of an average adjustment or one or several adjustments, it is sufficient for living environment sounds that have a wide range of sounds. The hearing ability of the wearer for a given frequency within the frequency band to be adjusted, regardless of variations due to individual hearing aid amplification characteristics and individual differences between hearing aids. It can be automatically adjusted to match the target data obtained from the inspection data.
[0067]
This automatic adjustment makes it possible to adjust the characteristics of the hearing aid, such as the degree of amplification and maximum output, to eliminate the individual differences in hearing aid manufacturing, and to create a target based on the hearing test of the wearer. A hearing aid tuned to the data can be provided to the wearer.
[0068]
Therefore, repeated trial listening and readjustment are almost unnecessary, and the readjustment after wearing can be completed in a very short time, and the burden on the wearer can be reduced. In addition, by this automatic amplification characteristic adjustment, the characteristics of the hearing aid are adjusted to a beautiful curve without peak dip that eliminates differences due to hearing aid models and individual differences, so it was not targeted by readjustment after wearing An optimum output can be obtained for sound of a frequency.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of the configuration of an automatic amplification characteristic adjusting device for a hearing aid according to the present invention.
FIG. 2 is a diagram showing an example of the configuration of a hearing aid.
FIG. 3 is a diagram showing an example of a flow of fitting work of a hearing aid according to the present invention.
4 is a diagram illustrating an example of a flow of examination regarding the ear of FIG. 3; FIG.
FIG. 5 is a diagram showing an example of a flow for creating target data in FIG. 3;
6 is a diagram showing an example of a flow of automatic amplification characteristic adjustment of the hearing aid of FIG. 3. FIG.
7 is a diagram showing an example of a readjustment flow after wearing in FIG. 3; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Automatic amplification characteristic adjustment apparatus 11 of a hearing aid Measurement sound generation part 12 Coupler 13 Sound pressure detection part 21 Target data preparation part 22 Comparison determination part 23 Correction data preparation part 24 Control part 25 Characteristic output part 26 Image display part 30 Hearing aid

Claims (1)

A measurement sound generator, a coupler that receives the sound obtained by amplifying the measurement sound generated by the measurement sound generator, a sound pressure detector that detects an output sound level of the sound input to the coupler, and the sound pressure A comparison / determination unit that compares the measurement data detected by the detection unit with the target data, a correction data creation unit that creates correction data for the hearing aid from the comparison data in the comparison / determination unit, and a correction created by the correction data creation unit And a control unit for inputting the data to the hearing aid, and calculating the amplification characteristic of the hearing aid from the measurement result of the comfort level and the uncomfortable level in the sound band of the deaf ear, thereby generating a wide frequency band generated by the measurement sound generation unit. the measurement sound, characterized in that the output of the hearing aid that is input to the microphone in the coupler to automatically adjust the gain of the hearing aid so that the target output for each predetermined frequency Automatic amplification characteristics adjustment device hearing aid.

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