Total least squares based subband modelling for scalable speech representations with damped sinusoids

We describe how Total Least Squares (TLS) algorithms can be applied as a powerful and eÆcient modelling tool for wideband speech. A detailed description in both time domain and frequency domain illustrates how the modelling functions { damped sinusoids { naturally synthesise non-stationary signals. Straightforward implementations of TLS applied to fullband speech are known to be computationally hard and they can suffer from numerical sensitivity. In this paper we introduce a subband approach, which leads to a signi cant reduction of the computational load with an enhanced numerical stability. Moreover, it enables to control the distribution of the TLS components over the spectral range of the input signal such that perceptual criteria can be incorporated in the modelling scheme. We also address the scalability of our design from smallband speech to high quality audio, and provide evidence for the existence of coupled components in TLS modelled segments.