Tone restricts F0 range and variation in Kammu
The aim of this study is to investigate whether the occurrence of lexical tones in a language imposes restrictions on its pitch range. We use data from Kammu, a Mon-Khmer language spoken in Northern Laos, which has one dialect with, and one without, lexical tones. The main finding is that speakers of the tonal dialect have a narrower pitch range, and also a smaller variation in pitch range.