Laryngeal adjustments in Japanese voiceless sound production

Abstract

As part of a series of investigations on the production of sequence of unvoiced sounds in different languages, the current experiment was conducted using the combined techniques of photo-electric glottography, fiberoptic filming and laryngeal electromyography. Particular attention was paid to devoiced vowel production in various voiceless consonantal environments including geminates. The data show that the glottal opening gesture during a voiceless sequence containing a devoiced vowel is characterized by a monomodal pattern, unless the vowel occurs between a voiceless fricative and a geminated one, such as /siQs/, where a bimodal pattern may occur. The movement results also suggest that the velocity and size of the glottal opening gesture vary according to the nature of the adjacent voiceless obstruents. The speed of the opening phase is slow when a stop precedes the vowel, and fast when a fricative precedes it. The peak glottal opening attained during the devoiced vowel is larger when a fricative either precedes or follows than when the vowel is surrounded on both sides by single or geminated stops. Furthermore, it is revealed that the peak velocity of the initial opening gesture occurs at almost the same time in relation to the voicing offset of the preceding vowel, regardless of the properties of the surrounding voiceless obstruents and, thus, irrespective of variations in the magnitude of velocity and opening size.