Laryngeal Control for Voicing Distinction in Japanese Consonant Production

Abstract

The aim of the present study was to investigate the laryngeal adjustments for voiced versus voiceless distinction in Japanese consonant production by means of laryngeal electromyography (EMG) and fiberoptic observation. Multichannel EMG recordings were taken of a Japanese subject and the data were computer-processed to obtain the averaged activity patterns of the five intrinsic laryngeal muscles with special reference to the voicing distinction in consonant production in various phonetic environments. It was found that there were apparent reciprocal patterns in the posterior cricoarytenoid (PCA) and the interarytenoid (INT) in terms of significant negative correlation, and active control of PCA for voicelessness was demonstrated. The patterns of the thyroarytenoid and the lateral cricoarytenoid were different from that of INT even though these two muscles are usually classified as the members of the adductor group, and their activity levels were apparently influenced by the phonetic environment. A possible contribution of the cricothyroid (CT) to the voicing distinction was also pointed out but further investigations on acoustic parameters seem to be mandatory in more critical interpretation of CT activity in speech.

Laryngeal activity in Swedish obstruent clusters

“…9, a positive relationship is found between average glottal opening area and PCA activity. A similar relationship has been presented by Hirose (1976), and by Hirose and Ushijima (1978), and it is perhaps not a surprising finding considering the anatomical arrangement of the PCA. In view of the rather crude measures used, in particular average peak, or minimum PCA activity, and in view of possible non-linearities in the transillumination signal, some variability in the relationship can be expected.…”

“…For these two muscles, a reciprocal pattern of activation generally has been observed, whereas the role of other adductor muscles, such as the lateral cricoarytenoid, is more uncertain. The lateral cricoarytenoid is usually suppressed for both voiced and voiceless obstruents, and has been functionally grouped with the vocalis muscle (Hirose and Gay, 1972;Hirose and Ushijima, 1978). It should be noted, however, that the notion of strict reciprocity between the posterior cricoarytenoid and the interarytenoid muscles rests mainly on studies using combinations of consonants and vowels, where voiced and unvoiced segments alternate in a regular manner.…”

Cricothyroid muscle activity at voicing transitions

“…This was further strengthened by the finding that during production of consonant clusters a separate glottal opening gesture was observed during production of voiceless consonants requiring higher rate of flow, such as fricatives and aspirated stops, which was primarily associated with distinctive increase in PCA activity. The EMG activity in other laryngeal muscles like TA and LCA was found to be low for the consonantal segment in speech and not related to voiced/voiceless distinction Kagaya and Hirose, 1975;Hirose and Ushijima, 1978;Collier et. al, 1979;Lofqvist, McGarr & Honda, 1984;Hirose, 1987), with an increase in activity prior to vowels, liquid glides and semivowel blends in connected speech Sawashima et al, 1975;Kagaya and Hirose, 1975;Löfqvist, McGarr & Honda, 1984;Hillel, 2001).…”

“…Some studies suggested that CT activity during speech did not show any distinct difference for voiced-voiceless contrast but was more closely related to frequency and intonation characteristics of the utterance Collier, Lisker, Hirose & Ushijima, 1979). Other studies have reported greater CT activity with voiceless sounds in comparison to their voiced cognates (Kagaya & Hirose, 1975;Hirose and Ushijima, 1978;Dixit & MacNeilage, 1981;Löfqvist, McGarr & Honda, 1984;Löfqvist et al, 1989;Hoole et al, 2004).…”

“…The maintenance of aerodynamic valving for this simultaneous voicing and aspiration contrasts was achieved by manipulating the relative timing of laryngeal and supra-laryngeal articulation (Kagaya & Hirose, 1975;Hirose, 1976;Dixit, 1989) Other studies have used EMG recordings to study the involvement of laryngeal muscles in active variation of glottal opening and found a reciprocal activity of posterior cricoarytenoid (PCA) and interarytenoid (IA) muscles corresponded closely with glottal width variation. Voiceless sound production was found to be associated with an increase in PCA muscle activity with reciprocal suppression of IA muscle; and voiced sounds with decrease in PCA and increase in IA muscle activity Hirose, 1976;Hirose & Ushijima, 1978;Hirose et al, 1983;Löfqvist, McGarr & Honda, 1984). Some studies reported higher activation of PCA muscle (with reciprocal IA activity) for production of fricatives and sounds with greater aspiration, than their lower air flow cognates, suggesting an influence of airflow requirement in the degree of glottal opening (Hirose, 1976;Yoshioka, Löfqvist & Hirose, 1981;Löfqvist & Yoshioka, 1980).…”