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 falling intonation; and 3-syllable utterances containing primary lexical stress on 1 of the 3 syllables. There was a wide variation of the glottal waveform shape, its rms [root-mean-square] intensity and fundamental frequency, phase spectrum and intensity spectrum. As the fundamental frequency changed over time, the glottal source varied in 1 of 2 different ways. In 1 type of change, the harmonic relations in the glottal spectrum became steeper as fundamental frequency rose. In a different type of glottal-wave change, relations between harmonics tended to remain the same despite a change in the fundamental frequency; the source spectrum in this case was 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 3 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.