Effects of consonant type on tone realization in Luganda

Since the f0 realization of tone categories requires voicing, interruptions of voicing disrupt that realization. Speakers have been shown to truncate the f0 excursion or compress its time-course in order to fit it into voiced sonorant intervals shortened by encroaching voiceless consonants [5–8]. In this study, the effect of consonants on f0 trajectories was investigated in Luganda (Bantu, Uganda). Speakers produced Luganda sentences including a C1-V1-C2-V2 interval, in which V1 was a short vowel with a high tone, and C1 and C2 varied in manner (sonorant, voiced obstruent, voiceless obstruent) and quantity (singleton, geminate). It was found that when C2 was voiceless, speakers sped up the f0 rise up to the voiceless interval, and slowed down the f0 fall during the voiceless interval. These adjustments had the effect of concentrating the f0 movements for the high tone in the voiced intervals before and after the voiceless interval. Voiceless C1, on the other hand, had no effect on the timing of the f0 trajectory.