Low bit quantization of the smoothed group delay spectrum for speech recognition

The coefficients of the smoothed group delay spectrum (SGDS) are calculated by discrete-time Fourier transform of the linear prediction coefficients, i.e. the representation is in the frequency domain. Isolated word recognition experiments with a low bit quantization of these SGDS coefficients are reported. It is shown that recognition accuracy can be maintained using only 26 b/frame as compared to the conventional calculation with floating-point accuracy. Using a bark scale representation the error rate can be even further reduced