Based On The Digital Audio Signal Processing Technology

With the development of digital technology, the signal process is not only depend on analog method, but also the digital signal processing method which avoided some shortages of analog method, and solve some problems which can not be handled well with analog method. But there is a vital flaw in the calculation quantity and throughput for the digital signal process method, especially when the digital signal process applies to some complex application(the digital audio signal process, the digital video signal process and so on). So the high efficiency and stabilization digital signal process method is a focus of researching now.This system base on the digital audio signal process technology(e.g. the design technology of digital filter), consider the range of frequency which hearing-human can hear is between 20Hz and 20000Hz, generate low frequency overtone signal with the original digital audio signal to substitute for the low frequency part of original digital audio signal, and generate harmonious and satiation digital audio signal at last. There are three main parts as follow: Firstly, Distilling the high frequency part of original digital audio signal by delaying, highest possible frequency filter and adjusting volume processes for the original digital audio signal. Secondly, Generating the low frequency overtone by delaying, multiphase filter down-sampling and up-sampling, child-band partition filter, child-band synthesize filter, band-pass filter and adjusting volume processes for the original digital audio signal. Thirdly, Generating harmonious and satiation digital audio signal by composing of the high frequency digital audio and low frequency overtone.The special processes of system as follows: delaying process for balancing the delay time caused by the digital audio signal process; highest possible frequency filter for non-overlap splicing the high frequency digital audio and low frequency overtone; adjusting volume for making up volume losing caused by the digital audio signal process; multiphase filter down-sampling process in the overtone generation part for reducing calculation quantity of system, the frequency and calculation quantity is reduced to a quarter of normal after down-sampling; child-band partition filter and child-band synthesize filter to generate the low frequency overtone with all frequency-bands of the original digital audio signal; band-pass filter with synthetical child-band signal for deal with the noise in the low frequency overtone; multiphase filter up-sampling process for resuming sampling frequency of the original digital audio signal.This digital audio signal process system can enrichment the frequency spectrum of the digital audio signal, improve the quality of digital audio, reduce the flux of digital audio data in the network application.