Analysis of phase derivatives of speech signals.

This paper examines the phase derivatives of speech signals. The instantaneous complex spectra obtained in the single frequency filtering (SFF) analysis of signals is used to derive the phase function. The problem of phase wrapping is avoided by using the proposed modification to SFF analysis to derive a scaled down version of the phase function.

Group delay spectrogram of speech signals without phase wrapping.

This paper proposes a method for displaying the phase information in speech signals through group delay spectrogram, without the need for phase unwrapping. The method involves scaling down the phase values without affecting the shape of the phase or group delay function, thus preserving the information of the phase spectrum. This is accomplished using single-frequency filtering (SFF) of speech signals to obtain the instantaneous complex SFF spectrum.

Analysis of aperiodicity in artistic Noh singing voice using an impulse sequence representation of excitation source.

Aperiodicity in the voice source is caused by changes in the vocal fold vibrations, other than the normal quasi-periodicity and the turbulence at the glottis. The aperiodicity appears to be one of the main properties that is responsible for conveying the emotion in artistic voices. In this paper, the feasibility of representing the excitation source characteristics in artistic (Noh) singing voice by an impulse-like sequence in the time domain is examined.

Subsegmental level analysis of high arousal speech using the zero-time windowing method.

Speech produced by a speaker in emotionally charged situations, such as anger, happiness, and shout corresponds to high arousal speech. Changes in the production characteristics such as increase in the subglottal air pressure, increase in the glottal closed phase in each cycle, and increase in the rate of glottal vibration are observed in the high arousal speech. Acoustic parameters such as glottal closed quotient and fundamental frequency (F) are used to characterize the high arousal speech.