KR20210055630A - Hearing Compensation Method of Hearing Aids Apparatus - Google Patents

Abstract

The present invention relates to a method of compensating for hearing of a hearing aid device, wherein the method for compensating for hearing of a hearing aid device of the present invention comprises the steps of: (A) calculating a gain for each frequency for a DFT (Discrete Fourier Transform) transformed signal of an acoustic signal. , (B) searching for a local maximum value of the gain for each frequency, (C) performing smoothing for the gain for each frequency, and (D) maintaining the local maximum value in the smoothing result for each frequency. And outputting a gain.

Description

Hearing Compensation Method of Hearing Aids Apparatus}

The present invention relates to a method of compensating for hearing of a hearing aid device, and in particular, to a method of compensating for hearing aid of a hearing aid device for performing more accurate hearing loss compensation and reducing discomfort for sudden noise for a user's hearing aid.

The basic algorithm of hearing aid medical devices such as hearing aids to compensate the hearing impaired person's hearing ability is Wide-Dynamic Range Compression. This compensates for the reduced dynamic range of hearing, and functions to adjust the dynamic range of the output signal to suit the individual with a hearing loss by adding nonlinear amplification to the input sound pressure. In the past, dynamic range adjustment was performed with a single channel, but in recent years, it has been increased to multiple channels, so that a volume optimized for each frequency can be applied to the hearing impaired.

In performing multi-channel wideband compression, a filter bank method was initially used to classify channels, which is a method of calculating an appropriate gain value by passing an input signal through several filter banks and summing them. The filter bank method has a disadvantage in that it has limitations in responding to changes in various frequency characteristics of hearing loss because the required computational amount increases exponentially as the number of channels increases.

In the conventional method using DFT (Discrete Fourier Transform), the method of calculating filter coefficients using DFT, performing IDFT (Inverse Discrete Fourier Transform) again, and convolution with the time sequence signal (Side-branch method) is in terms of the amount of computation. Since there is no significant advantage over the filter bank method in the frequency domain, a method of performing IDFT only once after performing all signal processing in the frequency domain has been recently proposed. In this method of using DFT-IDFT, a process of smoothing the gain value calculated in each channel is necessary to adjust the sound for each channel to an appropriate level, and since the gain value calculated in this smoothing process changes, the auditory compensation is properly performed. There was a problem that could not be achieved.

Accordingly, the present invention has been conceived to solve the above-described problem, and an object of the present invention is, in the auditory compensation method using DFT-IDFT, the volume is limited so that the maximum output is limited by performing smoothing while preserving the local maximum gain. Hearing aids that can assist the user's hearing so that the noise normalization is performed to remove unnecessary distortions, compensate for more accurate hearing loss, reduce discomfort for sudden noise, and provide natural hearing compensation. It is to provide a method of hearing compensation.

First, summarizing the features of the present invention, the auditory compensation method of the hearing aid device according to an aspect of the present invention for achieving the above object includes: (A) a frequency for a DFT (Discrete Fourier Transform) transformed signal of an acoustic signal. Calculating a star gain; (B) searching for a local maximum value of the gain for each frequency; (C) smoothing the gains for each frequency; And (D) maintaining the local maximum value in the smoothing result and outputting the gain for each frequency.

In the hearing compensation method of the hearing aid device, steps (B), (C), and (D) may be sequentially repeated two or more times in order to reduce distortion.

In step (B), the local maximum value may be searched for in units of a window corresponding to a frequency band. In this case, the frequency width of the window may be equally applied to the entire band. In addition, the frequency width of the window may be applied differently for each band.

In step (B), the local maximum value is searched in units of a window corresponding to a frequency band, but during the repetition of steps (B), (C), and (D), the position of the window unit according to the setting in the repetition mode. It is also possible to search for the local maximum value by moving to a frequency high band or low band position.

In addition, a hearing aid device according to another aspect of the present invention includes: a gain calculator configured to calculate a gain for each frequency of a DFT (Discrete Fourier Transform) transformed signal of an acoustic signal; A search unit searching for a local maximum value of the gain for each frequency; A smoothing unit for smoothing the gains for each frequency; And a holding unit configured to output the gain for each frequency by maintaining the local maximum value in the smoothing result.

In order to reduce distortion, the sequential operation of the search unit, the smoothing unit, and the holding unit may be repeated two or more times.

The search unit may search for the local maximum value in units of a window corresponding to a frequency band.

The search unit may apply the same frequency width of the window to the entire band.

The search unit may apply different frequency widths of the windows for each band.

The search unit searches for the local maximum value in units of a window corresponding to a frequency band, and during the sequential repetition operation of the search unit, the smoothing unit, and the holding unit, the position of the window unit is frequency It is also possible to search for the local maximum value by moving to a high or low band position.

According to the hearing compensation method of the hearing aid device according to the present invention, the volume leveling is performed so that the maximum output is limited by performing smoothing while preserving the local maximum gain with respect to the gain calculated from the spectrum signal for each frequency according to the Fourier transform of the speech signal. (Loudness normalization) can be performed to remove unnecessary distortion. Accordingly, more accurate compensation for hearing loss may be achieved, discomfort for unexpected noise may be reduced, and a user's hearing may be assisted so that natural hearing compensation may be achieved.

The accompanying drawings, which are included as part of the detailed description to aid in understanding of the present invention, provide embodiments of the present invention and describe the technical spirit of the present invention together with the detailed description.
1 is a diagram illustrating an ear-mounted type of a hearing aid device according to an embodiment of the present invention.
2 is a detailed configuration diagram of a hearing aid device according to an embodiment of the present invention.
3 is a flowchart for explaining the operation of the hearing aid device according to an embodiment of the present invention.
4A is a graph of gain values for a frequency band for explaining the gain compensation effect of the prior art.
4B is a graph of gain values for a frequency band for explaining the gain compensation effect in the present invention.
5 is a view for explaining an example of a method of implementing a hearing aid device according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In this case, the same components in each drawing are indicated by the same reference numerals as possible. In addition, detailed descriptions of already known functions and/or configurations will be omitted. In the following, a portion necessary for understanding an operation according to various embodiments will be mainly described, and descriptions of elements that may obscure the subject matter of the description will be omitted. In addition, some elements of the drawings may be exaggerated, omitted, or schematically illustrated. The size of each component does not entirely reflect the actual size, and therefore, the contents described herein are not limited by the relative size or spacing of the components drawn in each drawing.

In describing the embodiments of the present invention, when it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout the present specification. The terms used in the detailed description are only for describing the embodiments of the present invention, and should not be limiting. Unless explicitly used otherwise, expressions in the singular form include the meaning of the plural form. In the present description, expressions such as "comprising" or "feature" are intended to refer to certain features, numbers, steps, actions, elements, some or combination thereof, and one or more It should not be construed to exclude the presence or possibility of other features, numbers, steps, actions, elements, any part or combination thereof.

In addition, terms such as first and second may be used to describe various components, but the components are not limited by the terms, and the terms are used to distinguish one component from other components. Is only used.

1 is a diagram illustrating an ear-mounted type of a hearing aid device 100 according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the hearing aid 100 according to an embodiment of the present invention is implemented in the form of a hearing aid mounted in the user's ear to assist the user's hearing. In the auditory compensation method using DFT (Discrete Fourier Transform)-IDFT (Inverse Discrete Fourier Transform), the hearing aid device 100 of the present invention performs smoothing while preserving the local maximum gain so that the maximum output is limited. A loudness normalization is performed to remove unnecessary distortion, so that more accurate hearing loss compensation is achieved, and discomfort for sudden noise is reduced, and the hearing of the hearing impaired, such as the hearing impaired, can be assisted so that natural hearing compensation is achieved. I did.

2 is a detailed configuration diagram of the hearing aid device 100 according to an embodiment of the present invention.

Referring to FIG. 2, the hearing aid 100 according to an 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. Includes.

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

Hereinafter, the operation of the hearing aid device 100 according to an embodiment of the present invention will be described in detail with reference to FIG. 3.

3 is a flowchart for explaining the operation of the hearing aid device 100 according to an embodiment of the present invention.

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

First, the gain calculator 110 calculates a gain for each frequency of a DFT (Discrete Fourier Transform) transformed signal of an acoustic signal (S110). The DFT unit may generate a spectrum signal for each frequency by converting a time domain sound signal input through a microphone into a frequency domain signal through DFT processing. In this way, the frequency-specific spectrum signals Y1, Y2, .., YN, which are DFT-converted with respect to the acoustic signal by the DFT unit, are input to the gain calculating unit 110, and the gain calculating unit 110 is DFT for the acoustic signal. For the converted signals (Y1, Y2, .., YN), the gain is calculated for each frequency (see Fig. 4B).

The local maximum search unit 120 includes a preset window unit (frequency (band) width) corresponding to a frequency band for the calculated gain for each frequency from the gain calculation unit 110 (e.g., 500 Hz, 1000 Hz,, Etc.) (Refer to W1, W2, W3,,, in FIG. 4B), it is possible to search for a local maximum in the corresponding part. The local maximum search unit 120 may equally apply the corresponding frequency width in window units to the entire frequency band. Alternatively, in some cases, the local maximum search unit 120 may divide the entire frequency band for each band and apply a different width of the corresponding frequency in a window unit. For example, in the audible frequency band (20Hz~20kHz), as the frequency goes from the smallest to the large, the corresponding frequency width in a window unit can be applied to a wider range. Or, among the audible frequency bands (20Hz to 20kHz), the frequency range of the sound signal is approximately 100Hz to 10kHz, so the frequency width (first frequency width) of the window unit is equally divided and applied in the range of 100Hz to 10kHz, In the range of 20Hz to 100Hz, it is divided into a frequency width smaller than the first frequency width for the entire or multiple segmentation bands, and in the range of 10kHz to 20kHz, it is divided into a frequency width greater than the second frequency width for the entire or multiple segmentation bands. Can be applied.

The smoothing unit 130 smoothes the calculated gain for each frequency from the gain calculation unit 110 (S130). The smoothing unit 130 smoothes the gain for each frequency in order to remove noise such as a high frequency component of the gain or sharp peaks and valleys. To this end, the smoothing unit 130 may perform filtering by a low-pass filter or the like on a gain value in log units, or the smoothing unit 130 determines an average gain between a predetermined minimum output and a maximum output. Smoothing may be performed on a gain value in log units using an averaging technique.

The local maximum holding unit 140 outputs a gain for each frequency processed to maintain the local maximum value in the smoothing result (S140). 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 with respect to the gain for each frequency according to the smoothing result.

In order to reduce distortion, the sequential operations S120 to S140 of the local maximum search unit 120, smoothing unit 130, and local maximum holding unit 140 may be repeated two or more times according to a setting. In such a sequential repetition process, the local maximum search unit 120 determines the local maximum value for the calculated gain for each frequency from the gain calculation unit 110 in a corresponding set window unit corresponding to the frequency band as described above. ), it is also possible to search for the local maximum value by moving the position of the window unit to a frequency high band or low band position according to a predetermined setting in a corresponding repetition mode. For example, when the setting position is a movement to a high band position, within the frequency range of the sound signal (approximately 100 Hz to 10 kHz), a predetermined frequency band range (e.g., 100 Hz, 100 Hz, etc.) than the previously applied window unit position for each iteration process. It is also possible to search for the local maximum value by moving to a location where the frequency is large or small by 200 Hz,,,, etc.). Accordingly, distortion reduction is evenly processed over the entire band, thereby further assisting the user's hearing.

In this way, the gain for each frequency processed by the sequential iteration process of (S120 to S140) and output from the local maximum holding unit 140 is applied in a subsequent process (S150). In a subsequent process, appropriate amplification may be performed, and a signal in a time domain may be output using an Inverse Discrete Fourier Transform (IDFT).

4A is a graph of gain values for a frequency band for explaining the gain compensation effect of the prior art.

4B is a graph of gain values for a frequency band for explaining the gain compensation effect in the hearing aid device 100 of the present invention.

As shown in FIG. 4A, in the conventional method, even if the gain 410 for each frequency is smoothed, there is a case 420 that the output value exceeds the maximum output. Since the human hearing is in the form of an actual cosine filter, In the conventional method, when a loud sound is input from an adjacent frequency, there is a problem in that the sensitivity to the surrounding frequency decreases.

As shown in FIG. 4B, in the hearing aid device 100 of the present invention, an algorithm for maintaining a local maximum in addition to smoothing for the gain 410 for each frequency is applied to maintain the local maximum value. By outputting the gain 430 for each frequency, a more accurate gain value can be applied. In the present invention, since the actual human hearing has a response in log units, a smoothing process is performed based on a gain value in log units, and by performing such hearing compensation, an amplification ratio tailored to the hearing ability of the hearing impaired is determined. You can make it possible to get Human hearing is in the form of an actual cosine filter, and when a loud sound is input at an adjacent frequency, sensitivity to the surrounding frequencies decreases, so the hearing compensation algorithm of the present invention can effectively compensate the hearing loss of the hearing impaired person. . In the present invention, when an output value exceeding a predetermined maximum output is generated after auditory compensation by smoothing, a loudness normalization is performed in a local window so that the local maximum value is not immediately exceeded. This guarantees the same natural hearing compensation as the human cognitive system when a loud sound is applied, thereby reducing discomfort for living noise (such as a clicking sound or a door closing sound).

5 is a view for explaining an example of an implementation method of the hearing aid device 100 according to an embodiment of the present invention.

The hearing aid device 100 according to an embodiment of the present invention may be formed 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 as shown in FIG. 5 or a server on the Internet having at least one processor for performing the above functions/steps/processes. .

The computing system 1000 includes at least one processor 1100 connected through the bus 1200, a memory 1300, a user interface input device 1400, a user interface output device 1500, a storage 1600, and a network. An interface 1700 may be included. The processor 1100 may be a central processing unit (CPU) or a semiconductor device that processes instructions stored in the memory 1300 and/or the storage 1600. The memory 1300 and the storage 1600 may include various types of volatile or nonvolatile storage media. For example, the memory 1300 may include a read only memory (ROM) 1310 and a random access memory (RAM) 1320. In addition, the network interface 1700 is a communication module such as a modem that supports wired Internet communication, wireless Internet communication such as WiFi, WiBro, mobile communication such as WCDMA, LTE, etc. It may include a communication module such as a modem that supports communication in a wireless communication method (eg, Bluetooth, ZigBee, Wi-Fi, etc.).

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

As described above, the hearing aid 100 according to the present invention limits the maximum output by performing smoothing while preserving the local maximum gain with respect to the gain calculated in the spectrum signal for each frequency according to the Fourier transform of the speech signal. As much as possible, loudness normalization is performed to remove unnecessary distortion. Accordingly, more accurate compensation for hearing loss may be achieved, discomfort for unexpected noise may be reduced, and a user's hearing may be assisted so that natural hearing compensation may be achieved. According to the present invention, it is possible to eliminate the reduction in amplification gain that may occur in the conventional simple smoothing method, which gives more accurate gains to the hearing impaired, thereby maximizing the effect of the hearing aid.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but this is provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , Anyone with ordinary knowledge in the field to which the present invention belongs will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the spirit of the present invention is limited to the described embodiments and should not be determined, and not only the claims to be described later, but also all technical ideas that are equivalent or equivalent to the claims are included in the scope of the present invention. Should be interpreted as.

Gain calculation unit 110
Local maximum search unit 120
Smoothing section (130)
Local maximum holding part (140)

Claims (12)

(A) calculating a frequency-specific gain for a DFT (Discrete Fourier Transform) transformed signal of the acoustic signal;
(B) searching for a local maximum value of the gain for each frequency;
(C) smoothing the gains for each frequency; And
(D) outputting the gain for each frequency by maintaining the local maximum value in the smoothing result.
Hearing compensation method of a hearing aid device comprising a. The method of claim 1,
In order to reduce distortion, steps (B), (C), (D) can be repeated two or more times in sequence. The method of claim 1,
In step (B), the hearing compensation method of the hearing aid device searches for the local maximum value in units of a window corresponding to a frequency band. The method of claim 4,
Hearing compensation method of a hearing aid device in which the frequency width of the window is equally applied to the entire band. The method of claim 4,
Hearing compensation method of a hearing aid device in which the frequency width of the window is applied differently for each band. The method of claim 2,
In step (B), the local maximum value is searched in units of a window corresponding to a frequency band, but during the repetition of steps (B), (C), and (D), the position of the window unit according to the setting in the repetition mode A hearing compensation method of an auditory assisting device for moving to a location in a high or low frequency band and searching for the local maximum value. A gain calculator that calculates a frequency-specific gain for a DFT (Discrete Fourier Transform) transformed signal of the acoustic signal;
A search unit searching for a local maximum value of the gain for each frequency;
A smoothing unit for smoothing the gains for each frequency; And
A holding unit that outputs the gain for each frequency by maintaining the local maximum value in the smoothing result
Hearing aids comprising a. The method of claim 7,
In order to reduce distortion, the search unit, the smoothing unit, and the holding unit are sequentially performed two or more times. The method of claim 7,
The search unit searches for the local maximum value in units of a window corresponding to a frequency band. The method of claim 9,
The search unit is a hearing aid device in which the frequency width of the window is equally applied to the entire band. The method of claim 9,
The search unit is a hearing aid device in which a frequency width of the window is applied differently for each band. The method of claim 8,
The search unit searches for the local maximum value in units of a window corresponding to a frequency band, and during the sequential repetition operation of the search unit, the smoothing unit, and the holding unit, the position of the window unit is frequency A hearing aid device that moves to a high band or low band position and searches for the local maximum value.

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