CN115736905A

CN115736905A - Frequency sweep equalization threshold noise test method for rapid detection of cochlear dead zone

Info

Publication number: CN115736905A
Application number: CN202211343148.6A
Authority: CN
Inventors: 宫琴
Original assignee: Wuxi Qinger Huasheng Technology Co ltd; Wuxi Research Institute of Applied Technologies of Tsinghua University
Current assignee: Wuxi Qinger Huasheng Technology Co ltd; Wuxi Research Institute of Applied Technologies of Tsinghua University
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2023-03-07

Abstract

The invention relates to the technical field of noise detection, in particular to a frequency sweeping equalization threshold noise test method for rapidly detecting a cochlear dead zone, which can test continuous dead zone results in a large range, solves the problems of isolated test frequency and easy omission of the dead zone, can accurately detect the edge frequency of the dead zone, continuously plays the equalization threshold noise, realizes audible or inaudible feedback by continuously pressing or loosening a button, and continuously reduces the pure tone intensity when a subject presses the button; when a subject releases a button, the pure tone intensity continuously rises to obtain a sawtooth curve with the hearing threshold accessories continuously fluctuating when the balanced threshold noise is masked, the midpoint connecting line of each section of the sawtooth curve can obtain a test result in one direction, the signal-to-noise ratio of the hearing threshold after the balanced threshold noise is masked is greater than 10dB, meanwhile, the area with the hearing threshold after the masking higher than the hearing threshold before the masking by 10dB is judged as a dead zone, and the frequency corresponding to the endpoint of the curve with the dead zone is the edge frequency of the dead zone.

Description

Frequency sweep equalization threshold noise test method for rapid detection of cochlear dead zone

Technical Field

The invention relates to the technical field of noise detection, in particular to a frequency sweep equalization threshold noise test method for rapidly detecting a cochlear dead zone.

Background

The cochlea is an organ in the human body which converts mechanical energy input by external sound waves into nerve impulses. The round window of the cochlea receives the sound vibration transmitted by the ossicle and causes the basement membrane to vibrate, the vibration parts of the basement membrane caused by the sound with different frequencies are different, and the vibration of the basement membrane drives the hair cells to vibrate to generate the auditory sensation. Auditory hair cells are divided into outer hair cells and inner hair cells, wherein the outer hair cells are similar to amplifiers and mainly responsible for amplifying vibration caused by sound on a basement membrane, and the damage of the outer hair cells can reduce the gain of a cochlear amplifier; while inner hair cells resemble transducers, which mainly convert vibrations of the basement membrane into excitation of the auditory nerve, damage of which reduces the number of action potentials of the auditory nerve. Usually, sensorineural deafness is mainly caused by damage of outer hair cells, and at this time, the hearing aid amplifies the input to make the patient hear the sound again, however, in some cases, the inner hair cells in a certain frequency region of the cochlea or the neurons of the auditory nerve are seriously damaged, so that how the sound in this part of frequency region is amplified cannot make the patient hear the sound, and this part of frequency region is called as cochlea dead region, or simply called dead region.

The cochlea dead region is a region in which inner hair cells or auditory neurons in a cochlea lose functions or basically lose functions, and the detection of the cochlea dead region has important significance in hearing aid fitting and artificial cochlea implantation. The existing detection method for the cochlea dead region comprises the following steps: the Test result of the balanced threshold noise Test (TEN Test) is an isolated frequency point, a dead point is detected instead of a dead zone, and a tester does not know whether a non-dead zone region exists in the middle of the isolated Test points; on the other hand, due to the low frequency accuracy of the Test result, the TEN Test cannot provide a more accurate dead zone edge frequency.

Disclosure of Invention

The invention provides a sweep frequency equalization threshold noise test method for rapidly detecting a cochlear dead zone, which can be used for measuring a dead zone result which is continuous in a large range, solving the problems of isolated test frequency and easiness in missing the dead zone and accurately detecting the edge frequency of the dead zone, and aims to solve the problems that the existing test result is lack of continuity, the dead zone is easy to miss and the more accurate dead zone edge frequency cannot be provided.

The technical scheme is as follows: a frequency sweep equalization threshold noise test method for rapidly detecting cochlear dead regions is characterized in that equalization threshold noise is continuously played, a subject needs to judge whether pure tone with continuously changed frequency under noise background can be heard, the intensity of the equalization threshold noise is the hearing threshold + NdB of the subject under the current pure tone playing frequency, the frequency change rate of the pure tone is in direct proportion to the current frequency, the audible or inaudible feedback is realized by continuously pressing or releasing a button, and when the subject presses the button, the intensity of the pure tone is continuously reduced; when a subject releases a button, the pure tone intensity continuously rises to obtain a sawtooth curve with the hearing threshold accessory continuously fluctuating during the masking of the equalizing threshold noise, the midpoint connecting lines of all the sawtooth sections can obtain a test result in one direction, the signal-to-noise ratio of the hearing threshold after the masking of the equalizing threshold noise is greater than NdB, meanwhile, an area with the hearing threshold after the masking higher than the hearing threshold before the masking by N dB is judged as a dead zone, and the frequency corresponding to the endpoint of the curve with the dead zone is the edge frequency of the dead zone.

The method is further characterized in that when the test adopts sweep pure tone, forward sweep and reverse sweep are respectively used, smoothing processing is carried out according to the zigzag curve obtained by the test to obtain a smooth curve, and the smooth curve is averaged on a time axis: firstly, respectively shifting the two smooth curves on a time axis for time t which is less than or equal to 0.1s left or right, and then carrying out superposition average calculation to obtain a final detection result, wherein the forward frequency sweep is from low to high in frequency, and the reverse frequency sweep is from high to low in frequency;

the method is further characterized in that the time t is the condition that the difference of the two test results in all the movements is minimum;

and N is 10.

After the method and the device are adopted, the feedback of 'hearing/hearing failure' of a subject is changed from the original button pressing, namely the button pressing or releasing, so that a continuous test curve can be obtained, the dead zone range is obtained according to the comparison and judgment of the hearing threshold, the continuous dead zone result in a large range can be measured, the problems of isolated test frequency and easiness in missing the dead zone are solved, and meanwhile, the edge frequency of the dead zone is accurately detected according to the frequency corresponding to the end point of the curve where the dead zone is located.

Drawings

FIG. 1 is a schematic diagram of a forward sweep original curve and a smoothed curve during pure tone sweep;

FIG. 2 is a diagram showing an original curve of reverse frequency sweep and a smoothed curve during pure tone frequency sweep;

FIG. 3 is a graph showing the average post-treatment curve.

Detailed Description

A frequency sweep balance threshold noise test method for rapidly detecting cochlear dead zones continuously plays balance threshold noise, a subject needs to judge whether pure tone with continuously changed frequency under noise background can be heard, and the intensity of the balance threshold noise is +10dB of the hearing threshold of the subject under the current pure tone frequency (the frequency without pure tone audiometric data is filled by linear interpolation); in order to comply with the psychophysical property that the auditory frequency resolution is consistent with the logarithm of the current frequency, the rate of change of the frequency of the pure tone is proportional to the current frequency, for example, the time for the pure tone frequency to change from 500Hz to 1000Hz is the same as the time for the pure tone frequency to change from 1000Hz to 2000 Hz; to measure the hearing threshold when a continuous subject equalization threshold noise (TEN) mask is obtained, the subject's feedback to "hear or not hear" is accomplished by continuously pressing or releasing a button, the pure tone intensity continuously decreasing when the subject presses the button; when a subject releases a button, the pure tone intensity continuously rises to obtain a sawtooth curve with a hearing threshold accessory continuously fluctuating when the equalization threshold noise is masked, a test result in one direction can be obtained by connecting the middle points of all the sawtooth sections, the signal-to-noise ratio of the hearing threshold after the equalization threshold noise (TEN) is masked is larger than 10dB, meanwhile, an area with the hearing threshold after the equalization threshold noise (TEN) is masked being higher than the hearing threshold before the equalization threshold noise (TEN) is judged to be a dead zone, and the frequency corresponding to the end point of the curve where the dead zone is located is the edge frequency of the dead zone.

When the test adopts sweep frequency pure tone, because there is certain reaction time from hearing sound to pressing or releasing button, there will be certain delay in the curve obtained by test and the actual result, so use forward sweep frequency and reverse sweep frequency respectively, according to the zigzag curve obtained by test to carry on the smoothing process and get the smooth curve, take the average process in the time axis for the smooth curve: firstly, respectively shifting the two smooth curves on a time axis for time t which is less than or equal to 0.1s to the left or right, and then carrying out superposition average calculation to obtain a final detection result, wherein the forward frequency sweep is from low to high in frequency, and the reverse frequency sweep is from high to low in frequency, which are respectively shown in fig. 1, fig. 2 and fig. 3. The time t is the case where the difference between the two test results is the smallest in all the movements. The frequency change of the sweep pure tone can be adjusted along with the precision of the change of the sweep tone.

The invention changes the dead point detection into the dead zone detection, greatly improves the accuracy of the test, provides an accurate result for the hearing aid fitting or enables the artificial cochlea to be accurately implanted.

Claims

1. A frequency sweep equalization threshold noise test method for rapidly detecting cochlear dead zones is characterized in that equalization threshold noise is continuously played, a subject needs to judge whether pure tone with continuously changed frequency under noise background can be heard, the intensity of the equalization threshold noise is the hearing threshold + NdB of the subject under the current pure tone playing frequency, the frequency change rate of the pure tone is in direct proportion to the current frequency, the hearing or hearing-imperceptible feedback is realized by continuously pressing or loosening a button, and when the subject presses the button, the intensity of the pure tone is continuously reduced; when a subject releases a button, the pure tone intensity continuously rises to obtain a zigzag curve with the hearing threshold accessories continuously fluctuating during the masking of the equalization threshold noise, the midpoint connecting line of each zigzag segment can obtain a test result in one direction, the signal-to-noise ratio of the hearing threshold after the equalization threshold noise is masked is greater than NdB, meanwhile, an area with the hearing threshold after the equalization threshold noise is masked being higher than the hearing threshold before the masking by N dB is judged as a dead zone, and the frequency corresponding to the endpoint of the curve with the dead zone is the edge frequency of the dead zone.

2. A frequency sweep equalization threshold noise test method for rapid detection of cochlear dead zones as claimed in claim 1, wherein when the test employs pure frequency sweep, forward frequency sweep and reverse frequency sweep are respectively used, smoothing is performed according to a zigzag curve obtained by the test to obtain a smooth curve, and the smooth curve is averaged on a time axis: and firstly, respectively shifting the two smooth curves on a time axis for time t which is less than or equal to 0.1s left and right, and then performing superposition average calculation to obtain a final detection result, wherein the forward frequency sweep is from low to high in frequency, and the reverse frequency sweep is from high to low in frequency.

3. A frequency sweep equalization threshold noise test method for rapid detection of cochlear dead band as claimed in claim 2, characterized in that the time t is the minimum difference between the two test results in all the movements.

4. A frequency sweep equalization threshold noise test method for rapid detection of cochlear dead regions as claimed in claim 1, wherein N is 10.