Donald G. Jamieson
Hear. Health Care Res. Unit, Univ. of Western Ontario, Elborn College, London, ON N6G 1H1, Canada
This paper compares four alternative procedures for estimating the acoustical characteristics of speech and other complex signals: the fast Fourier transform (FFT), two autoregressive techniques (the autocorrelation and modified covariance methods), and the Cone--Kernel method. All four techniques are now widely available to researchers in Version 4.0 of the CSRE (Canadian Speech Research Environment) software system. FFT spectral estimates are characterized by many known tradeoffs: good frequency resolution is obtained at the expense of good time resolution, and vice versa. Autoregressive methods overcome some of the inherent limitations of the FFT method, but still use a quasi-stationary approach to analyze nonstationary signals such as speech. The Cone--Kernel method offers the opportunity for both good frequency and good time resolution, and cancels many of the cross terms that have made it difficult to interpret previous approaches based on the Wigner distribution. Examples of applying the various analysis procedures to signals will be shown, including situations where the Cone--Kernel approach facilitates the interpretation of certain details of the speech signal.
The Museum will be keep open exclusively for the Society until 7:30 p.m. so that members can visit the exhibits. Members are also invited to view the 20-minute film ``Momentum,'' which presents spectacular views of Canada projected at 48 frames per second in the new high definition IMAX HD technique. Shuttle bus service will operate continuously between the Chateau Laurier and the Museum. The first bus will leave the Chateau Laurier from Mackenzie.