Comparison of the wavelet decomposition and the Fourier transform in TCX encoding of wideband speech and audio

This paper reports on the specific contribution of the wavelet transform (WT) in the TCX coding model for audio signals. TCX, or “transform coded excitation”, is a frame based coding algorithm that uses both time domain (linear prediction) and frequency domain (transform coding) approaches to exploit signal redundancies as well as frequency masking. While previous work on TCX used the discrete Fourier transform (DFT), the quality for highly non-stationary signals such as percussions was less than satisfactory. The WT has therefore been investigated as compromise between time and frequency resolution