Abstract: A framework of IIR two-channel biorthogonal filter banks is used here. The design of the analysis/synthesis systems reduces to the design of a single transferfunction. The wavelet bases corresponding to the IIR maximally flat filters aregenerated. Use the wavelet bases in wavelet packets analysis, take information entropy function as information cost function, adjust the best bases dynamically,and the section of signal's spectrum fits its characteristic well. A lot of audio signals are processed. Compared to that of the wavelet transform and the wavelet packet transform using the Daubechies wavelet which has the same order withour IIR wavelet, our properties are better.

Key words: digital signal processing, two-channel biorthogonal filter banks, wavelet packet transform