Some Observations of Laryngeal Phenomena Derived from High-Speed Motion Pictures

The activity of the larynx was photographed by a Fastax high-speed camera during the production of short, normal vowels; short, breathy vowels: tense and lax glottal stops; and the VCV utterance /ɛhɛ/. During the breathy vowel the arytenoids are separated. A triangular aperture is thus formed at the posterior portion of the glottis in contrast to the complete closure typical of normal vowels. The glottal stop is produced by the contraction of the sides and anterior of the larynx at and below the level of the false vocal cords. During the closure of the tense glottal stop some vocal cord motion was observed. The rate of closure and relaxation for the tense and lax glottal stops appears to be approximately constant. The pattern of laryngeal activity for both vowels of the utterance /ɛhɛ/ differed from that typical of normal short vowels insofar as vocal cord motion started before closure of the arytenoids, giving a breathy effect.