Speech processing with Walsh-Hadamard transforms
Frank Y.Y. Shum, A. Elliott, W. A. Brown · IEEE Transactions on Audio and Electroacoustics · 1973
High-speed algorithms to compute the discrete Hadamard and Walsh transforms of speech waveforms have been developed. Intelligible speech has been reconstructed from dominant Hadamard or Walsh coefficients on a medium sized computer in a non-real-time mode. Degradation of some phonemes was noted at low bit rates of reconstruction, but the reconstruction could be improved by varying the position of the sampling window. A digital processor, which allows real-time analysis of speech to be conducted on the system, is described.