Study of variations in the male and female glottal wave

A reflectionless metal tube which can act as a pseudoinfinite termination of the vocal tract was used to collect glottal volume-velocity waveforms produced by 10 male and female adult subjects. From each subject glottal volume-velocity samples were collected of normal, loud, and soft voice; falsetto and creaky voice; monosyllables with rising and failing intonation; and three-syllable utterances containing primary lexical stress on one of the three syllables. Analysis of the data indicates a wide variation of the glottal waveform shape, its rms intensity and fundamental frequency, phase spectrum, and intensity spectrum. It is observed that as the fundamental frequency changes over time, the glottal source varies in one of two different ways. In one type of change, the harmonic relations in the glottal spectrum become steeper as fundamental frequency rises. In a different type of glottal-wave change, relations between harmonics tend to remain the same despite a change in the fundamental frequency; the source spectrum in this case is simply shifted along the frequency and amplitude axes as a function of fundamental frequency. To account for these variations in the glottal source, at least three factors must be known: the sex of the speaker, the voice register in which he phonates, and the linguistic context in which the phonation occurs.