Laryngeal activity in the production of voiceless obstruents and obstruent clusters in Icelandicwas investigated by the combined techniques of transillumination and fiberoptic filming of the larynx. Contrasts of preaspirated, unaspirated, and postaspirated voiceless stops were found to be produced basically by differences in laryngeal-oral timing. In clusters of voiceless obstruents, one or more continuous laryngeal opening and closing gestures occurred depending on the segments in the cluster.Peak velocity of glottal abduction was higher for fricatives than for stops. This, and other differences in laryngeal adjustments and interarticulator timing between stops and fricatives, are most likely due to different aerodynamic requirements for stop and fricative production. The present results further question the usefulness of timeless feature descriptions for modeling speech production.

In modern Icelandic, spoken in the South, West, and North-West of Iceland, there is a phonemic opposition between voiced and voiceless nasals before stop consonants. For the present investigation the research instrument was the velograph. The purpose of the research was to investigate patterns of velar movement associated with each type of nasal consonants. The results show different types of velar movement organized according to two separate temporal patterns. For the voiceless nasals the movement of the velum is more rapid and begins earlier than for the voiced nasals. There are also significant differences in the nasalization of the preceding vowel according to whether the following nasal consonant is voiced or voiceless.