Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JP2000270391 [0001] FIELD OF THE INVENTION This invention relates primarily to hearing aids. [0002] 2. Description of the Related Art Although external noise is one of the factors that reduce the intelligibility of hearing aids, in conventional hearing aids, the input / output characteristics and frequency characteristics of the deafness ear are compensated by the characteristics of the hearing aid, and signal-to-noise ratio It is mainstream to try to prevent further deterioration. Although some amplifiers suppress the noise by dividing the amplifier into frequency bands and controlling the amplification of the noise band, it is a problem when overlapping with the signal band. In this case, although the noise can be reduced by the directivity of the microphone and the array, since the scale of the device is limited with respect to the wavelength, the sharpness of the directivity is not sufficient. [0003] SUMMARY OF THE INVENTION When it is intended to remove extraneous noise that degrades the intelligibility of a hearing aid by the directional characteristics of the microphone, the conventional method obtains sharp directional characteristics because of limitations on the size of the microphone array. I can not. The present invention significantly improves this directivity. 03-05-2019 1 [0004] SUMMARY OF THE INVENTION A receiver array comprising microphones of multiple channels is placed on the frame of a spectacles-type fitting or on the support beam of a headphone-type fitting. The output of each microphone is subjected to Fourier transform to obtain an amplitude spectrum and a phase spectrum, and the following operation is performed for each frequency band. The phase difference between each channel is multiplied by an arbitrary coefficient to enlarge the difference, and further, the amplitude and phase between each channel are interpolated to calculate the interpolated channel output, and the number of channels including the interpolated channel is made to any size Multiply. These outputs are multiplied by an arbitrary weight function to perform phasing addition (simply adding in the case of creating a beam in the front direction), and inverse Fourier transform to form a conventional amplifier input. [0005] DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a system diagram showing an embodiment of the present invention. 1, 2, 3, and 4 M1, M2, Mi, and Mm (i = 1, 2,... M) are mchannel microphones at horizontal distance intervals that are the frame of the spectacles-type mounting tool or the support beam of headphones Arranged to form 5 microphone arrays. [0006] fi (t) (i = 1, 2,..., m) is the output of each microphone, and is converted to the frequency spectrum Fi (ω) (i = 1, 2,..., m) of m channels by 6 Fourier transformers Be done. 7, 8, 9 and 10 Ai (ω) (i = 1, 2,..., M) and αi (ω) (i = 1, 2,... M) respectively represent Fi (ω) (i = 1, 1) 2, ..., m) amplitude spectrum and phase spectrum. Here, ω is an angular frequency. The following operations are performed on these outputs at 11 for each frequency band. The phase difference between the channels is determined from αi (ω) (i = 1, 2,..., m), and this difference is multiplied by an arbitrary coefficient Kp to expand the phase difference between the channels, and a new phase spectrum βi ( ω) (i = 1, 2,..., m) is obtained. The frequency spectrum becomes Gi (ω) (i = 1, 2,..., M), and the amplitude spectrum Ai (ω) (i = 1, 2,..., M) and the phase spectrum become 12, 13, 14 and 15. It shows β i (ω) (i = 1, 2,..., m). Next, for each frequency band, the amplitude and phase between each channel can be set arbitrarily from Ai (ω) (i = 1,2, ..., m) and βi (ω) (i = 1,2, ... m) 03-05-2019 2 in 16 To calculate the spectrum of the interpolation channel, multiply the number of channels including the interpolation channel to an arbitrary size n = K cm, and calculate a new frequency spectrum H k (ω) (k = 1, 2, ..., n). 17, 18, 19 and 20 show its amplitude spectrum Bk (ω) (k = 1, 2,..., N) and phase spectrum γk (ω) (k = 1, 2,... N). Next, at 21, shaping is performed by multiplying the amplitude Bk (ω) (k = 1, 2,..., N) of each channel by an arbitrary weighting function Wk (k = 1, 2,. The frequency spectrum J k (ω) (k = 1, 2,..., N) is obtained. 22, 23, 24 and 25 show the amplitude spectrum C k (ω) (k = 1, 2,..., N) and the phase spectrum γ k (ω) (k = 1, 2,..., N). At 26, these inputs are subjected to phasing addition in any direction (simply adding when forming a beam in the front direction) to obtain a directional output J (ω). At 27, J (ω) is subjected to inverse Fourier transform to form a directional output j (t), which is used as a conventional amplifier input. [0007] An example calculation is shown below for the case of a linear array. The array length is al, the microphone spacing is d, the number of microphone channels is m, the sound wave arrival direction is measured from the front of the array θ, the phase difference expansion coefficient is Kp, the channel multiplication coefficient is Kc, and the wavelength is λ. From the above, the microphone spacing d is d = al / (m−1), the number of multiplication channels n is n = K cm, and the multiplication channel spacing s is s = al · Kp / (n−1). The phase spectrum βi (ω) is given by equation (1). When the phasing azimuth is 0 degree, the directivity characteristic R (θ) of the addition output is as follows according to each condition. １． In the case of a nondirectional microphone R (θ) = R (θ). ２． In the case of a unidirectional microphone R (.theta.) = R (.theta.) CR (.theta.) C = R (.theta.) O (1 + cos (.theta.)) / 2 (3) In the case of a 3.2 second order sound pressure gradient microphone R (θ) = R (θ) g where a is the distance between the sound pressure gradient microphones. 4 When Shading is not Performed In the case of Wk = 1, R (θ) o in the equations (2), (3) and (4) is the equation (5). [0008] The calculation results of the directivity characteristic are shown in FIG. 2, 3 and 4 show the case where the phase difference expansion coefficient Kp = 1 and the channel multiplication coefficient Kc = 1, respectively, using an omnidirectional element, a unidirectional element and a secondary sound pressure gradient element. There is. On the other hand, in FIG. 5, FIG. 6 and FIG. 7, the pointing width is reduced with Kp = 5 and Kc = 5. With respect to the improvement of the pointing width, in FIGS. 8, 9 and 10, the shading is further added to attenuate the side lobes. However, since the pointing width is slightly increased by this, in FIGS. 11, 12 and 13, the 03-05-2019 3 pointing width is reduced again as Kp = 8 and Kc = 8. Here, the array length al = 15 cm, the number of microphone channels m = 2, the frequency f = 1000 Hz, the wavelength λ = 34 cm, and the inter-sensor distance a = 5 cm of the secondary sound pressure gradient element. In addition, the shaping coefficient Wk is 0.54 + 0.46 cos (π (2k−n−1) / (n−1)). Comparing "Fig. 2, 3 and 4" with "Fig. 5, 6 and 7" and "Fig. 8, 9 and 10" with "Fig. 11, 12 and 13", Kp and Kc are obtained. It can be seen that the pointing width is significantly reduced by increasing. In the case where the microphones can be arranged in the vertical direction as in the headphone type wearing tool, it is possible to further improve the directivity characteristic in the vertical direction as well. 03-05-2019 4

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