The use of tracking rules in automatic formant analysis of speech

Abstract

The J.S.R.U. computer‐simulated automatic formant analyser uses analysis by synthesis to achieve high reliability and accuracy in the matching of synthetic formants to the peaks of pitch synchronous short term spectra of natural speech [P.M. Seeviour, J. N. Holmes and M. W. Judd, IEEE Int. Conf. Acoust., Speech, Signal Processing, Philadelphia, PA, pp. 609–693 (1976)]. However, analysis by synthesis does not of itself necessarily provide consistent labeling of the peaks of the natural spectrum. The specific case of this problem as it appears in the J.S.R.U. formant analyser will be discussed. The task is to choose, for each 10 ms frame of speech, from among a number of attempts to produce a synthetic match to the natural spectrum. The restrictions on the algorithm, particularly the need to avoid excessive smoothing of formant movement, will be mentioned. Simple heuristic rules currently in use will be described and the performance obtainable with such rules will be illustrated by means of spectrograms and audio tape recordings.