Investigation of the Glottal Waveshape by Automatic Inverse Filtering
Joan E. Miller, M. V. Mathews · The Journal of the Acoustical Society of America · 1963
Considerable attention has been given of late to the source function, its properties and significance. Consequently, a method of pitch-synchronous analysis, reported on previously, has been improved and applied more extensively to gather additional data on the volume-velocity function of the glottis. The technique arises from the model of vocalic sounds in which the spectra are characterized by a separation of vocal-tract poles from glottal-source zeros. A Fourier analysis is made on one period of the pressure wave, the formants are located and removed from the spectrum, and the glottal waveform is computed from the residual by Fourier synthesis. This approach requires digital recordings free from phase distortion and with a high signal-to-noise ratio. Data from six male talkers in varying contexts and at different pitches and intensities have been studied with attention to shape, phase with respect to the speech wave, duty factor and degree of closure as a function of talker, sound, pitch, and intensity.