Hearing Compensation Method of Hearing Aids Apparatus

Abstract

The present invention relates to a method for auditory compensation of an assistive hearing device, wherein the auditory compensation method of the assistive hearing device of the present invention comprises: (A) a step of calculating a frequency-specific gain for a signal that has undergone Discrete Fourier Transform (DFT) transformation of an acoustic signal; (B) a step of searching for a local maximum value of the frequency-specific gain; (C) a step of performing smoothing on the frequency-specific gain; and (D) a step of outputting the frequency-specific gain by maintaining the local maximum value in the smoothing result.

Description

Technology Field

[0001] The present invention relates to a hearing compensation method for an assistive hearing device, and more specifically, to a hearing compensation method for an assistive hearing device that provides more accurate hearing loss compensation and reduces discomfort caused by sudden noise for the purpose of assisting a user's hearing. Background Technology

[0002] The basic algorithm for hearing aids and other assistive hearing devices designed to compensate for the hearing loss of individuals is Wide-Dynamic Range Compression. This compensates for the dynamic range of reduced hearing by adding non-linear amplification to the input sound pressure, thereby adjusting the dynamic range of the output signal to suit each individual with hearing loss. In the past, dynamic range adjustment was performed using a single channel, but recently, it has expanded to multiple channels, enabling the delivery of sound levels optimized for each frequency to individuals with hearing loss.

[0003] In performing multi-channel broadband compression, the filter bank method was initially used for channel separation. This method involves passing the input signal through multiple filter banks to calculate appropriate gain values ​​for each and summing them up. However, the filter bank method had the disadvantage of showing limitations in responding to various frequency characteristic changes in hearing loss, as the amount of computation required increases exponentially as the number of channels increases.

[0004] In conventional methods using the Discrete Fourier Transform (DFT), the side-branch method—which calculates filter coefficients using the DFT, performs the Inverse Discrete Fourier Transform (IDFT), and convolves them with the time series signal—does not offer significant advantages over the filter bank method in terms of computational complexity. Therefore, a method that performs all signal processing in the frequency domain and then performs the IDFT only once has recently been proposed. In this method using DFT-IDFT, a process of smoothing the gain values ​​calculated from each channel is absolutely necessary to adjust the sound of each channel to an appropriate level. However, since the gain values ​​calculated during this smoothing process change, there was a problem in that auditory compensation could not be properly achieved. The problem to be solved

[0005] Accordingly, the present invention has been devised to solve the aforementioned problems. The objective of the present invention is to provide a hearing compensation method for an assistive hearing device that can assist the user's hearing by enabling natural hearing compensation, wherein loudness normalization is performed to limit the maximum output by preserving local maximum gain while performing smoothing in a hearing compensation method using DFT-IDFT, thereby eliminating unnecessary distortion, enabling more accurate hearing loss compensation, reducing discomfort caused by sudden noise, and providing natural hearing compensation. means of solving the problem

[0006] First, to summarize the features of the present invention, a hearing compensation method for an assistive hearing device according to one aspect of the present invention for achieving the above objective comprises: (A) a step of calculating a frequency-specific gain for a signal that has undergone Discrete Fourier Transform (DFT) transformation of an acoustic signal; (B) a step of searching for a local maximum value of the frequency-specific gain; (C) a step of performing smoothing on the frequency-specific gain; and (D) a step of outputting the frequency-specific gain by maintaining the local maximum value in the smoothing result.

[0007] The auditory compensation method of the above-mentioned hearing aid can repeat steps (B), (C), and (D) sequentially two or more times to reduce distortion.

[0008] (B) In step (B), the local maximum value can be searched in units of windows corresponding to the frequency band. At this time, the frequency width of the window may be applied equally to the entire band. Alternatively, the frequency width of the window may be applied differently for each band.

[0009] In step (B), the local maximum value is searched in units of windows corresponding to the frequency band, and during the repetition of steps (B), (C), and (D), the position of the window unit may be moved to a high-frequency band or low-frequency band position to search for the local maximum value according to the setting in the repetition mode.

[0010] And, according to another aspect of the present invention, an assistive hearing device comprises: a gain calculation unit that calculates a frequency-specific gain for a Discrete Fourier Transform (DFT) transformed signal of an acoustic signal; a search unit that searches for a local maximum value of the frequency-specific gain; a smoothing unit that performs smoothing on the frequency-specific gain; and a maintenance unit that maintains the local maximum value in the smoothing result and outputs the frequency-specific gain.

[0011] To reduce distortion, the sequential operation of the search unit, the smoothing unit, and the maintenance unit can be repeated two or more times.

[0012] The above search unit can search for the local maximum value in units of windows corresponding to the frequency band.

[0013] The above search unit can apply the frequency width of the window equally across the entire band.

[0014] The above search unit may apply different frequency widths of the window for each band.

[0015] The above search unit searches for the local maximum value in window units corresponding to the frequency band, and during the sequential repetitive operation of the search unit, the smoothing unit, and the maintenance unit, the position of the window unit may be moved to a high-frequency band or low-frequency band position to search for the local maximum value according to the setting in the repetitive mode. Effects of the invention

[0016] According to the auditory compensation method of the hearing aid device of the present invention, loudness normalization is performed on the gain calculated from the frequency-specific spectrum signal based on the Fourier transform of a speech signal while preserving the local maximum gain, thereby limiting the maximum output and eliminating unnecessary distortion. Accordingly, more accurate hearing loss compensation is achieved, discomfort caused by sudden noise can be reduced, and the user's hearing can be assisted to achieve natural hearing compensation. Brief explanation of the drawing

[0017] The accompanying drawings, included as part of the detailed description to aid in understanding the present invention, provide embodiments of the present invention and explain the technical concept of the present invention together with the detailed description. Figure 1 shows an in-ear mounting form of a hearing aid according to one embodiment of the present invention. FIG. 2 is a detailed configuration diagram of a hearing aid device according to one embodiment of the present invention. FIG. 3 is a flowchart for explaining the operation of a hearing aid device according to one embodiment of the present invention. Figure 4a is a graph of gain values ​​for a frequency band to explain the gain compensation effect of the prior art. FIG. 4b is a graph of gain values ​​for a frequency band to explain the gain compensation effect in the present invention. FIG. 5 is a drawing for explaining an example of a method for implementing a hearing aid device according to an embodiment of the present invention. Specific details for implementing the invention

[0018] The present invention will be described in detail below with reference to the attached drawings. In this case, identical components in each drawing are denoted by the same reference numeral whenever possible. Furthermore, detailed descriptions of already known functions and / or configurations are omitted. The content disclosed below focuses on the parts necessary for understanding the operation according to various embodiments, and descriptions of elements that may obscure the gist of the explanation are omitted. Additionally, some components in the drawings may be exaggerated, omitted, or schematically depicted. The size of each component does not entirely reflect its actual size, and therefore, the contents described herein are not limited by the relative sizes or spacing of the components depicted in each drawing.

[0019] In describing the embodiments of the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the invention. Furthermore, the terms described below are defined in consideration of their functions within the present invention, and these may vary depending on the intentions or practices of the user or operator. Therefore, such definitions should be based on the content throughout this specification. Terms used in the detailed description are intended merely to describe the embodiments of the present invention and should not be limiting in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form. In this description, expressions such as "include" or "comprise" are intended to refer to certain characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts thereof, or combinations thereof other than those described.

[0020] Additionally, terms such as first, second, etc., may be used to describe various components, but said components are not limited by said terms, and said terms are used only for the purpose of distinguishing one component from another.

[0021] FIG. 1 shows the ear canal mounting form of a hearing aid (100) according to one embodiment of the present invention.

[0022] Referring to FIG. 1, a hearing aid device (100) according to one embodiment of the present invention is implemented in the form of a hearing aid that is fitted into the user's ear and assists the user's hearing. The hearing aid device (100) of the present invention is designed to assist the hearing of a user, such as a person with hearing loss, by performing loudness normalization in a hearing compensation method using Discrete Fourier Transform (DFT)-Inverse Discrete Fourier Transform (IDFT) while preserving local maximum gain, thereby limiting maximum output and eliminating unnecessary distortion, so that more accurate hearing loss compensation is achieved, discomfort from sudden noise can be reduced, and natural hearing compensation is achieved.

[0023] FIG. 2 is a detailed configuration diagram of a hearing aid device (100) according to one embodiment of the present invention.

[0024] Referring to FIG. 2, a hearing aid (100) according to one embodiment of the present invention includes a gain calculation unit (110), a local maximum search unit (120), a smoothing unit (130), and a local maximum maintenance unit (140).

[0025] Each component of the hearing aid device (100) according to one embodiment of the present invention may be implemented as hardware such as a semiconductor processor, software such as an application program, or a combination thereof.

[0026] The operation of a hearing aid device (100) according to one embodiment of the present invention will be described in detail below with reference to FIG. 3.

[0027] FIG. 3 is a flowchart for explaining the operation of a hearing aid device (100) according to one embodiment of the present invention.

[0028] Referring to FIG. 3, the operation of a hearing aid (100) according to one embodiment of the present invention includes a step of calculating a frequency-specific gain (S110), a step of searching for a local maximum value of the frequency-specific gain (S120), a smoothing step (S130), a step of outputting a frequency-specific gain by maintaining the local maximum value in the smoothing result (S140), and a step of applying a frequency-specific gain after removing distortion by repeating steps S120 to S140 two or more times (S150).

[0029] First, the gain calculation unit (110) calculates the frequency-specific gain for the Discrete Fourier Transform (DFT) transformed signal of the acoustic signal (S110). The DFT unit can generate a frequency-specific spectrum signal by converting the time-domain acoustic signal input through the microphone into a frequency-domain signal through DFT processing. The frequency-specific spectrum signals (Y1, Y2, ..., YN) transformed by the DFT unit for the acoustic signal are input to the gain calculation unit (110), and the gain calculation unit (110) calculates the frequency-specific gain for the DFT-transformed signals (Y1, Y2, ..., YN) for the acoustic signal (see FIG. 4b).

[0030] The local maximum search unit (120) can search for a local maximum value in a corresponding portion for each preset window unit (frequency (band) width) (e.g., 500Hz, 1000Hz, etc.) (refer to W1, W2, W3, etc. in FIG. 4b) corresponding to the frequency band for the frequency-specific gain calculated from the gain calculation unit (110). The local maximum search unit (120) can apply the corresponding frequency width in the window unit equally to the entire frequency band. Alternatively, depending on the case, the local maximum search unit (120) may apply the corresponding frequency width in the window unit differently by dividing the entire frequency band by band. For example, in the audible frequency band (20Hz~20kHz), the corresponding frequency width in the window unit can be applied more widely as the frequency increases from the lower end to the higher end. Alternatively, since the frequency range of the acoustic signal within the audible frequency band (20Hz to 20kHz) is approximately 100Hz to 10kHz, a frequency width of window units (first frequency width) can be equally divided and applied in the 100Hz to 10kHz range, a frequency width smaller than the first frequency width can be divided and applied for the entire range or for multiple divided bands in the 20Hz to 100Hz range, and a frequency width larger than the second frequency width can be divided and applied for the entire range or for multiple divided bands in the 10kHz to 20kHz range.

[0031] The smoothing unit (130) performs smoothing on the frequency-specific gain calculated from the gain calculation unit (110) (S130). The smoothing unit (130) performs smoothing on the frequency-specific gain to remove noise such as high-frequency components of the gain or sharp peaks and valleys. To this end, the smoothing unit (130) may perform filtering on the logarithmic gain value using a low-pass filter, etc., or the smoothing unit (130) may perform smoothing on the logarithmic gain value using an averaging technique that determines the average gain between a predetermined minimum output and a maximum output.

[0032] The local maximum holding unit (140) outputs a frequency-specific gain processed to maintain the local maximum value in the smoothing result (S140). For the frequency-specific gain according to the smoothing result, the local maximum holding unit (140) replaces the maximum value for each preset window unit (frequency bandwidth) with the local maximum value searched by the local maximum search unit (120).

[0033] To reduce distortion, the sequential operation (S120~S140) of the local maximum search unit (120), smoothing unit (130), and local maximum maintenance unit (140) may be repeated two or more times according to the settings. In this sequential repetition process, the local maximum search unit (120), when searching for a local maximum value in a corresponding set window unit corresponding to the frequency band for the calculated frequency-specific gain from the gain calculation unit (110) as described above, may search for the local maximum value by moving the position of the window unit to a high-frequency band or low-frequency band position according to a predetermined setting in the repetition mode. For example, if the set position is moved to a high-frequency band position, the local maximum value may be searched by moving to a position where the frequency is larger or smaller than the previously applied window unit position by a predetermined frequency band range (e.g., 100Hz, 200Hz, etc.) within the frequency range of the acoustic signal (approximately 100Hz to 10kHz) during each repetition process. Accordingly, distortion reduction is evenly distributed across the entire frequency band, which can further assist the user's hearing.

[0034] In this way, the frequency-specific gain output from the local maximum holding section (140), processed through the sequential repetition process (S120~S140), is applied in the subsequent process (S150). In the subsequent process, appropriate amplification is performed, and the signal can be output as a time-domain signal using the Inverse Discrete Fourier Transform (IDFT).

[0035] Figure 4a is a graph of gain values ​​for a frequency band to explain the gain compensation effect of the prior art.

[0036] FIG. 4b is a graph of gain values ​​for a frequency band to explain the gain compensation effect in the hearing aid (100) of the present invention.

[0037] As shown in FIG. 4a, even if the conventional method smooths the frequency-specific gain (410), there are cases (420) where the output value exceeds the maximum output. Since human hearing is in the form of a cosine filter, the conventional method has a problem in that sensitivity to surrounding frequencies decreases when a loud sound is input at an adjacent frequency.

[0038] As shown in FIG. 4b, in the hearing aid device (100) of the present invention, in addition to smoothing, an algorithm that maintains a local maximum value is applied to the frequency-specific gain (410), and by outputting a frequency-specific gain (430) processed to maintain the local maximum value, a more accurate gain value can be applied. In the present invention, since actual human hearing has a response in logarithmic units, a smoothing process is performed based on a gain value in logarithmic units, and by performing such hearing compensation, an amplification ratio tailored to the hearing of a person with hearing loss can be obtained. Since human hearing is in the form of a cosine filter, sensitivity to surrounding frequencies decreases when a loud sound is input at an adjacent frequency, such a hearing compensation algorithm of the present invention can effectively compensate for the hearing of a person with hearing loss. In the present invention, if an output value exceeding a predetermined maximum output is obtained after hearing compensation by smoothing, loudness normalization is performed in a local window immediately so as not to exceed the local maximum value. This allows for the reduction of discomfort caused by everyday noises (such as clicking sounds or door closing sounds) by ensuring natural hearing compensation identical to that of the human cognitive system when loud sounds are applied.

[0040] FIG. 5 is a drawing for explaining an example of a method for implementing a hearing aid (100) according to an embodiment of the present invention.

[0041] A hearing aid device (100) according to one embodiment of the present invention may be made of hardware, software, or a combination thereof. For example, the hearing aid device (100) of the present invention may be implemented in the form of a computing system (1000) such as FIG. 5 having at least one processor for performing the above functions / steps / processes, or in the form of a server on the Internet.

[0042] A computing system (1000) may include at least one processor (1100), memory (1300), user interface input device (1400), user interface output device (1500), storage (1600), and network interface (1700) connected via a bus (1200). The processor (1100) may be a central processing unit (CPU) or a semiconductor device that executes processing on instructions stored in memory (1300) and / or storage (1600). Memory (1300) and storage (1600) may include various types of volatile or non-volatile storage media. For example, memory (1300) may include Read Only Memory (ROM) (1310) and Random Access Memory (RAM) (1320). Additionally, the network interface (1700) may include a communication module such as a modem that supports wired internet communication in a user terminal such as a smartphone, laptop PC, or desktop PC, wireless internet communication such as WiFi or WiBro, or mobile communication such as WCDMA or LTE, or a communication module such as a modem that supports short-range wireless communication methods (e.g., Bluetooth, Zigbee, WiFi, etc.).

[0043] Accordingly, the steps of the method or algorithm described in connection with the embodiments disclosed herein may be directly implemented in hardware, software modules, or a combination of both, executed by the processor (1100). The software module may reside in a storage / recording medium readable by a device such as a computer (i.e., memory (1300) and / or storage (1600)), such as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, or a CD-ROM. An exemplary storage medium may be coupled to the processor (1100), and the processor (1100) may read information (code) from the storage medium and write information (code) to the storage medium. Alternatively, the storage medium may be integral with the processor (1100). The processor and the storage medium may reside within an application-specific integrated circuit (ASIC). The ASIC may reside within a user terminal. Alternatively, the processor and the storage medium may reside as separate components within the user terminal.

[0044] As described above, the hearing aid (100) according to the present invention can eliminate unnecessary distortion by performing loudness normalization on the gain calculated from the frequency-specific spectrum signal according to the Fourier transform of the voice signal, thereby limiting the maximum output while preserving the local maximum gain. Accordingly, more accurate hearing loss compensation is achieved, discomfort caused by sudden noise can be reduced, and the user's hearing can be assisted to achieve natural hearing compensation. According to the present invention, the reduction in amplification gain that may occur in conventional simple smoothing methods can be eliminated, which provides more accurate gain to the hearing-impaired person and maximizes the effectiveness of the hearing aid.

[0045] As described above, the present invention has been explained by specific details such as specific components, limited embodiments, and drawings; however, this is provided merely to aid in a more comprehensive understanding of the invention, and the invention is not limited to the above embodiments. A person skilled in the art to which the invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the invention. Accordingly, the concept of the present invention should not be limited to the described embodiments, and all technical concepts that are equivalent to or have equivalent variations to the claims set forth below, as well as the claims themselves, should be interpreted as being included within the scope of the rights of the present invention. Explanation of the symbols

[0046] Profit calculation unit (110) Local maximum search unit (120) Smoothing part (130) Local maximum retention area (140)

Claims

Claim 1 (A) a step of calculating frequency-specific gain for a Discrete Fourier Transform (DFT) transformed signal of an acoustic signal; (B) a step of searching for local maximum values ​​as the maximum values ​​of each window unit for the frequency-specific gain for each window unit as a preset frequency width for the frequency range of the acoustic signal; (C) a step of performing smoothing on the frequency-specific gain; and (D) a step of replacing the maximum values ​​for each window unit with the respective local maximum values ​​for the frequency-specific gain of the smoothing result and outputting the result. Claim 2 A hearing compensation method for an assistive hearing device according to claim 1, wherein steps (B), (C), and (D) are repeated sequentially two or more times in a repeating mode, and the local maximum values ​​are searched by applying a change in frequency position to a position of a larger frequency or a smaller frequency, different from the previously applied frequency position, to the window units of step (B). Claim 3 In paragraph 2, the auditory compensation method of the auditory assistive device comprises: (a) preserving a local maximum gain by the local maximum value, (b) limiting the maximum output by the smoothing, and (c) realizing the removal of distortion within the window units at a frequency position that has changed by changing the frequency position of the window units in the repetition mode. Claim 4 A hearing compensation method for an assistive hearing device according to claim 1, wherein in step (B), the size of the frequency width of each of the window units is applied equally across the entire band. Claim 5 A hearing compensation method for an assistive hearing device according to claim 1, wherein in step (B), the frequency width of each of the window units is applied differently by band. Claim 6 delete Claim 7 An assistive hearing device comprising: a gain calculation unit for calculating frequency-specific gain for a Discrete Fourier Transform (DFT) transformed acoustic signal; a search unit for local maximum values ​​as the maximum values ​​of each window unit for the frequency-specific gain, for each window unit as a preset frequency width for the frequency range of the acoustic signal; a smoothing unit for performing smoothing on the frequency-specific gain; and a maintenance unit for outputting the frequency-specific gain of the smoothing result by replacing the maximum values ​​of each window unit with their respective local maximum values. Claim 8 In claim 7, in a repeating mode in which the search unit, the smoothing unit, and the maintenance unit are sequentially repeated two or more times, the search unit searches for local maximum values ​​by applying a change in frequency position to a position of a larger frequency or a smaller frequency, different from the previously applied frequency position for the window units. Claim 9 In claim 8, the hearing aid comprises: (a) preserving local maximum gain by the local maximum value, (b) limiting maximum output by the smoothing, and (c) realizing the elimination of distortion within the window units at a frequency position varied by changing the frequency position of the window units in the repetition mode. Claim 10 In claim 7, the search unit is an assistive hearing device that applies the size of the frequency width of each of the window units equally to the entire band. Claim 11 In claim 7, the search unit is an assistive hearing device that applies different frequency widths to each of the window units according to band. Claim 12 delete

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