Filter bank simulating auditory perception model

Abstract

The invention relates to a filter bank simulating an auditory perception model, comprising an analysis filter bank 2, an each channel gain calculation module 3, a multiplier unit 4 and a synthesis filter bank 5. An audio frequency digital signal X(n)1 is divided into K channels after passing through the analysis filter bank 2, each channel gain calculation module 3 calculates to obtain a specificgain value of each channel, the multiplier unit 4 enables the channel gain value to multiply a corresponding sub-band signal, and an obtained result is synthesized into a path of output signal y(n)6 by the synthesis filter bank 5; the filter bank respectively carries out all-pass transformation and all-pass inverse transformation in the analysis filter bank 2 and the synthesis filter bank 5 of a weighting splicing adding structure by the method of combining the weighting splicing adding structure and the all-pass transformation so as to simulate the ear auditory resolution ratio under the condition of fewer channels. The invention has the high efficiency of the weighting splicing adding structure and meanwhile solves the problems of no real-time realization and phase distortion existing inthe present frequency transformation filter bank method.

Description

technical field [0001] The present invention relates to digital signal processing technology in digital hearing aids, in particular, to a filter bank for simulating auditory perception model for filtering and separating audio signals of hearing aids. Background technique [0002] Hearing loss is often a decrease in hearing sensitivity related to frequency. Typical hearing loss increases with the increase of frequency. Therefore, hearing aids should treat different frequency components of audio signals differently according to the specific conditions of different hearing-impaired patients. In the case of ensuring the frequency resolution, minimizing the computational complexity is one of the key issues. [0003] The selection of the digital filter bank has an important influence on the signal quality, computational complexity and signal delay of the signal processing system of the digital hearing aid. According to the bandwidth, digital filter banks can be divided into unifo...

AI Technical Summary

Problems solved by technology

[0007] At present, there are mainly two types of implementation methods for the analysis-synthesis filter bank of nonlinear frequency transformation. One is to perform all-pass transformation on the entire signal, and then use a uniform filter bank to process it. In this way, a uniform channel is made on the transformed frequency scale Dividing is equivalent to doing non-uniform channel division on the original frequency scale. This kind of method needs to perform time reversal operation on the entire signal, so it cannot be used for real-time signal processing; the second is to use the all-pass filter A(z) instead of polyphase Delay unit z in structure or WOLA structure -1 , the disadvantage of this is that the all-pass filter will cause phase distortion, compensating for these distortions makes the design of the integrated filter bank more complicated, and increases computational complexity and signal delay

Images