TW200537965A - The frequency response shaping analog hearing aid - Google Patents

Abstract

This invention is a frequency response shaping analog hearing aid. The signals are processed in time domain. The signals are treated by three stages as following: the anterior treatment stage, the channels filtering and adjusting stage, and the demodulation and output stage. In the anterior treatment stage, the signals received from the environment are filtered, amplified, and then modulated with the mixer. The modulated signals have higher frequency, equivalent to shorter wavelength, than the original ones. In the second stage, the modulated signals are treated by one to several filters that are different in their frequency range of passband and then adjusted the gain depending on the user's hearing loss and the outside conditions. In the demodulation and output stage, signals are synthesizing and demodulating to drive the output speaker. The adoption of the mixer reduces the size of the channel filter in order to adapt to the micromachining techniques, leading to mass production and cost reducing.

Description

200537965

V. Description of the invention α) [Technical field to which the invention belongs] This creation proposes a new analogy of analogue method, whose signal processing is completely in the time domain. Formal hearing aid signal processing conditions and the environment are different. According to the hearing loss of the user, the external hearing device can be instantly displayed to adjust the hearing aid to the best hearing effect. [Previous technology] Early hearing aid structures were similar to the funnel area. After the sounds were collected, they passed through the narrow mouth. Outward increase in external ear reception

Great effect. Among them, the Republic of China connects the ear canal and reaches the sonic amplitude teaching No. 2 773 08 [2] Patent 5 Dishonor Notice No. 2 0 0 2 68 [1] and Liang, which are all hearing aids that use microphones The number of the method is changed, and the wind is amplified by an amplifier to convert the external sound into an electronic signal earphone and output to the ear canal sub-signal. Then the electroacoustic converter (such as large, so it cannot be full. The output sound is only external sound waves In addition to the amplification of the noise, the different hearing loss conditions, and the full frequency of the signal will cause discomfort. For users who hurt the audio hearing loss, the hearing loss status of the Republic of China Patent Bulletin will also be reserved. , For its corresponding hearing loss is large, but its main size is too large, filtering

The patent No. 4 6 5 2 4 8 [3] is a hearing aid developed for different applications. Divide the hearing loss into various categories and use a fixed frequency response format to correct the situation. Therefore, the application is more flexible than the traditional analog hearing aid. The disadvantage is that it is limited by the low-frequency analog band-pass filter. The circuit includes a full-frequency filter and a high-pass filter.

Page 7, 200537965 V. Description of the invention (2) The low-frequency band response can be obtained only by calculation after filtering the result, and the quality of the low-frequency band sound output is relatively poor. Republic of China Patent Bulletin Nos. 0 7 1 7 8 3 [4] and 4 7 9 4 3 5 [5] patents belong to the type of digital hearing aids currently in use, which use a microphone to convert sound waves into electronics Signal, and then digitize this signal, and obtain the signal size of each channel in the audio range through a digital signal processor (Digita 1 signa 1 pr 〇cess 〇r) operation processing. Convert back to analog electronic signals and push the headphone output. The advantage of digital hearing aids is that the range that can be adjusted according to hearing loss and environmental requirements is not limited, however, distortion may occur during the digitization process, and the operation time of the digital signal processor causes the time delay of external sound and headphone output. It cannot be completely eliminated. References: [1] Sunie Co., Ltd. π Hearing Aid π, Republic of China Patent Bulletin No .: 2 0 0 2 6 8 [2] Philips Electronics Co., Ltd., π Hearing Aid π, Republic of China Patent Bulletin No .: 2 7 7 3 0 8 [3] Shanov Company, π Hearing Aid with Sound Format π, Republic of China Patent Bulletin No .: 4 6 5 2 4 8 [4] Intec System, "with the difference in programmable frequency response Hearing Aid π, Republic of China Patent Bulletin No .: 0 7 1 783 [5] Shanov Company, "Digital Filter for Hearing Aid π,

Page 8 200537965 V. Explanation of the invention (3) Profit announcement number: 4 7 9 4 3 5 [Summary of the invention] 1. Correct various hearing loss situations, and take into account the flexibility and convenience in use. 2. Reduce the size of hearing aids. 3 · Reduce distortion and delay caused by processing. [Embodiment] As shown in the <first image>, from the initial receiving of the external acoustic wave signal S to the acoustic wave signal So finally entering the ear canal, the hearing aid divides the signal into three stages for processing: signal pre-processing stage, filtering adjustment Phase and demodulation output phase. The detailed flow of the signal pre-processing stage is <second picture>. The external sound wave signal S is received by a receiver (such as a microphone or a microphone) and converted into an electronic signal Se, and then sent to a low-pass filter to exceed the signal frequency beyond the human ear. Part of the hearing range is filtered out, and the filtered signal can be represented by S i (f) in the frequency domain after being enhanced by the signal amplifier. Send this signal to the mixer and mix it with the signal Sr (fr) generated by the oscillator to obtain 2 f, 2 fr, f + fr, f-fr and other different frequency ranges and DC signal output. Among them, only a signal with a frequency range of f + fr is required. Therefore, a signal with a frequency in the frequency range f + fr can be obtained by filtering a signal outside the frequency with the frequency range f + fr through a band-pass filter. The signal pre-processing of the first stage has been completed, followed by the processing of the letter

200537965 V. Description of the invention (4) Sm (f + fr) is converted into a low-wave speed physical signal of sa (f + fr) by the transducer (10) and input to the filter adjustment device for signal processing, as shown in the third figure As shown in the figure, the center frequency of the filter pass band of the filter adjustment device is fp + fr and the upper and lower cut-off frequencies of the band are fh + fr and fl + fr, where fl &lt; fh and fp = (fh + f 1) / 2. The adjustable amplifier (1 2) whose gain is G is adjusted to amplify the signal s p (f p + f r) according to the hearing loss condition and the surrounding environment, to obtain the output signal G S p (f p + f r) in the filter adjustment stage. There are three different design methods for the filter adjustment device and the adjustable amplifier, which are described as follows: Method 1: 〈The fourth diagram〉 is a schematic diagram of the design of the channel filter and the adjustable amplifier. It uses η band-pass filters, called The channel filter covers the passband of the filtering device. If the center frequency of the i-th channel filter is represented by f 丨, where i = 1, 2, 3 ... η and the frequency order is f 1 + fn &lt; f 2 &lt; ··· &lt; ffh + fr 'The filtering frequency ranges of each channel and adjacent channels are interlaced one by one at the junction to cover all signals in the modulated audio. In this way, the signal Sa (f + fr) generated by the transducer is divided into multiple channels and filtered independently. It is represented by A i (fi), and each channel is equipped with a set of adjustable amplifiers with gain G 丨 according to the needs of the user. Adjust the gain of each channel flexibly to get the output signal GiAi (fi), and the combination of the output signals of each channel is the output signal GSp (fp + f) in the filter adjustment stage in the "third picture". Method two: Such as the fifth As shown in the figure>, the filter adjustment device of this design method is formed by concatenating m filter modules, in which the number m can be selected to be one or two or more according to the complexity of the hearing loss. Figure 6> shows the frequency of the i-th filter module

200537965 V. Description of the invention (5) Response diagram, the upper and lower cut-off frequencies are fh + fr and f Ι + fr, and the frequency response gain of the passband is higher in the i-th channel than the other channels, and the difference between this gain Values are designed based on varying levels of hearing loss. Based on this, a variety of filter modules with different frequency response gains are designed. Modules with higher response gain in low-frequency channels than other channels are suitable for low-channel hearing loss correction. Similarly, the response gains of intermediate-frequency and high-frequency channels are higher than those of other channels. The modules with high response gain are suitable for IF and HF channel hearing loss correction, respectively. If it is for the hearing loss of two channels, and the center frequencies are fa and fb respectively, then design a filtering device with a frequency response as shown in "Seventh Figure", where the response gain of these two channels is higher than other channels; and so on To design a filtering device for hearing correction of multiple channels. According to the different hearing loss conditions of the user, one or several filter modules are selected in series to filter and reshape the modulated sound wave signal, and then the signal GSP (fp + fr) is amplified by the adjustable amplifier with a gain of G as required. Method 3: This method combines the channel filter and filter module used by the two methods described above as the filter adjustment device. According to the connection method of "eighth figure", the channel filter and the filter module are connected in parallel to obtain a filter such as " The frequency response diagram shown in Figure 9>, this correction method is for users with severe hearing loss in channel a with center frequency fa and channel b with center frequency fb also with mild hearing loss, without affecting the rest In the case of channel response, the gain difference between channel a and the remaining channels is greatly increased, and the hearing loss of channel b can be made up. Then, an adjustable amplifier is connected in series to adjust the output as required.

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, 'V 200537965 V. Description of the invention (6) From the tenth figure, the output stage adjustment process sends the signal GSp (fp + fr) into the mixer (13) and the signal Sr generated by the oscillator (14) (fr) performs mixed-wave demodulation, in which only a signal having a frequency lower than fh is required, and thus a signal having a frequency higher than fh is filtered out through a low-pass filter (1 5), and an audio electronic signal So (fp) can be obtained ), And finally the electronic signal So (fp) is converted into a sound wave output through a speaker (16) (such as a headset).

Page 12 200537965 Brief description of the diagrams [Illustration] <First diagram> is a diagram of the hearing aid signal processing stage <Second diagram> is a signal pre-processing stage flowchart <Third diagram> is a filter adjustment stage flowchart < Figure 4 is a schematic diagram of the design of a channel filter and a tunable amplifier. Figure 5 is a schematic diagram of the filter module series connection. Figure 6 is a schematic diagram of the frequency response of the i-th filter module. Figure 7 is a dual-channel correction. Schematic diagram of the frequency response of the filtering device (eighth diagram) is a schematic diagram of the parallel connection of the channel filter and the filter module. <11th diagram> is the frequency response diagram of the low-pass filter <12th diagram> is the frequency response diagram of the band-pass filter <13th diagram> is the i-channel interdigital transducer and surface acoustic wave filter Schematic diagram (fourteenth diagram) is a frequency response diagram of a filter module for correcting high-frequency hearing loss. Figure> Schematic diagram of the frequency response of the channel filter to correct the dual-channel hearing loss (Seventeenth figure) Schematic diagram of the frequency response of the filtering device to correct the 1 0 0 8 0 0 Hz and 1 0 3 0 0 0 Hz dual-channel hearing loss [Figure Number Description]

(1) External sound wave S

Page 13, 200537965 Brief description of the diagram (2) Sound wave output So (3) Channel 丨 (4) Channel with center frequency fa (5) Channel with center frequency fb (6) Frequency response of channel filter (7 ) Frequency response of filter and wave module (8) Frequency response of channel filter and filter module in parallel (9) Refers to cross transducer (1 0) Surface acoustic wave filter, wave filter (11) Piezoelectric material substrate (12 ) Channel with center frequency of 1 0 5 0 0 0 Hz_ (13) Channel with center frequency of 1 0 0 3 0 0 Hz (1 4) Center frequency of 1 0 0 5 6 5 频道 Channel (15) center of z Channels with a frequency of 1 0 3 0 0 0 Hz

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Claims (1)

， 200537965 6. Scope of patent application Patent application scope: 1 · An analog signal processing method for frequency-corrected hearing aids, which mainly adopts analog signal processing in the time domain, and adjusts the signal according to the needs of the channel and adjusts the signal output. The steps include: (1) The signal pre-processing stage is to receive and convert the sound wave signal that enters the hearing aid into an electronic signal by the receiver. After processing through a low-pass filter and signal amplifier, it is sent to the mixer and oscillated. The high-frequency signal generated by the converter is subjected to mixing modulation to increase the signal frequency and shorten the signal wavelength, which is beneficial to the signal filtering process; (2) The filtering adjustment stage is to send the signal processed by the mixing modulation to the transducer And its matched channel filter; the transducer converts the electronic signal into another physical signal with a wave velocity much lower than the electromagnetic wave velocity; each channel filter corresponds to a passband; the channel filter has multiple transducers Detector, the wavelength is converted from the center frequency of the corresponding channel and the transmission speed to determine the sensor that picks up the signal in that frequency band Proper location of the cloth, the frequency ranges of adjacent channels are partially covered by each other; each channel is equipped with an adjustable amplifier to flexibly adjust the signal output size of each channel; (3) The demodulation output stage will be performed by each channel filter The filtered signal is demodulated by a mixer and low-pass filtered to drive the speaker output. 2. The signal processing method of the analog frequency-division corrective hearing aid according to item 1 of the scope of patent application, wherein the filter adjustment stage can be replaced by another filter adjustment stage, which is a signal outputted by the signal pre-processing stage, Filtered by several filter modules in succession, and then passed through an adjustable amplifier Page 15 200537965 VI. The scope of patent application or the signal amplification of several adjustable amplifiers connected in series to achieve flexible compensation of hearing loss; and the filtering method of each order is to select one to several channels in the filtering frequency band so that the The frequency response gain of the channel is higher than other channels, and the difference of this gain can be designed and corrected according to different hearing loss conditions. 3. The signal processing method of the analog frequency-division corrective hearing aid according to item 1 of the scope of patent application, wherein the filter adjustment stage can be replaced by another filter adjustment stage, which simultaneously outputs the signals outputted by the signal pre-processing stage. Filtering is performed through one or more filter modules and one or more filter modules, and then the signal is amplified by one or several adjustable amplifiers connected in series to achieve elastic compensation of hearing loss. 4. An analog frequency-division corrective hearing aid device, which is mainly electrically connected to a filter adjustment stage device by a signal pre-processing stage device, and the output end of the filter adjustment stage device is electrically connected to a demodulation output stage device. It consists of: The signal pre-processing stage device includes a receiver, a low-pass filter, a signal amplifier, an oscillator, and a mixer. The receiver converts the sound wave signal entering the hearing aid into electronics. Signal, and input the low-pass filter and the signal amplifier to perform low-pass filtering and signal amplification processing, respectively, and send the high-frequency signal generated by the oscillator to the mixer for mixing modulation, so that Increasing the signal frequency shortens the signal wavelength, which is beneficial to the signal filtering process; the filtering adjustment stage device includes at least one transducer, more than one Page 16 ^ 200537965 VI. Patent-applicable channel filter and one or several adjustable amplifiers, the transducer converts the mixed electronic signal into another physical signal whose wave velocity is much lower than the electromagnetic wave velocity; Any channel filter corresponds to a filter pass band, and the frequency range of adjacent channels is partially covered with each other; each channel is equipped with an adjustable amplifier to achieve flexible adjustment of the signal output size of each channel; and the The demodulation output stage device includes an oscillator, a mixer, a low-pass filter, and a loudspeaker. The mixer can carry out the signal filtered by each channel filter and the signal generated by the oscillator. Mixed-wave demodulation; the low-pass filter can filter the high-frequency signal from the output signal of the mixer and send it to the speaker to be converted into a sound wave output. Test 5. The signal processing device of the analog frequency-division corrective hearing aid according to item 4 of the scope of patent application, wherein the filter adjustment stage device can be replaced by another filter adjustment stage device, which includes at least one filter module and At least one adjustable amplifier, the one or more electrically connected filter modules can filter the signal output by the signal pre-processing stage device, and send the signal to the one or more connected adjustable amplifiers for signal amplification In order to achieve flexible compensation of hearing loss; and the one or more electrically connected filter modules are selected to filter one to several channels in the frequency band, so that the frequency response gain of the selected channel is higher than other channels, and The difference of this gain can be designed and corrected according to different hearing loss conditions. 6. Analog frequency-divided corrective hearing aids as described in item 4 of the scope of patent applications Page 17 V Λ Ν ^ 200537965 6. The patent-applied signal processing device, wherein the filter adjustment phase device can be replaced by another filter adjustment phase device, which includes more than one channel filter and more than one filter module. And more than one adjustable amplifier, the channel filter and the filter module are electrically connected in parallel, and can filter the signal output by the signal pre-processing stage device, and then be electrically connected to the one or several serial connections The adjustable amplifier performs signal amplification to achieve elastic compensation for hearing loss. Page 18