Correlation based speech formant recovery
D.J. Nelson · 2002
A new method for generating speech spectrograms is presented. This algorithm is based on an autocorrelation function whose parameters are chosen provide processing gain and formant resolution, while minimizing pitch artifacts in the spectrum. Crisp formants are produced, and the power ratio of the formants can be adjusted by pre-filtering the data. The autocorrelation process is functionally equivalent to a time-smoothed, windowed Wigner distribution. The process is an improvement over the normal FFT implementation since it requires much less data to resolve the speech formants, and it is an improvement over the un-smoothed Wigner distribution since the cross-terms normally associated with the Wigner distribution are greatly attenuated by the smoothing operation.