Pitch control and pharynx with in Twi: an electromyographic study

The author examined electromyographic tracings from four muscles--genioglossus (GG), anterior belly of the digastric (D) sternothyroid (ST) and thyrohyoid (TH)--for 210 Twi syllables selected so as to give information on seven parameters: tense/lax vowels, long/short vowels, close/open vowels, front/back vowels, high-tone/low-tone vowels, vowels preceded by a fricative/plosive consonant and vowels preceded by a voiced/voiceless consonant, and concluded, inter alia (1) that GG and D functioned as pitch control muscles but that it is not clear why raising of the larynx should accompany an increase in pitch; (2) that GG did not play the major role in tongue root fronting that was expected of it but that we may have to consider GG to consist of at least four functional muscles; (3) that GG and D offered little evidence to support a prosodic view of vowel harmony in Twi, and (4) that features may be ranked by the muscle activity associated with them and that 'high-tone', 'fricative' and 'voiced' dominated for GG, D and ST.