Garo, an understudied Tibeto-Burman language spoken in Northeast India is an atonal language and thus is an exception in the context of its related languages (Burling, 2003; Joseph and Burling, 2001). Garo however, has been described as possessing a phonemic glottal stop in its phonemic inventory (Burling, 1992). Crosslinguistically, it is found that glottal stops are realized a creaky voice quality in a lot of languages (Davidson, 2021), which in turn can affect the F0 on the vowel (Keating et al., 2015). This paper examines the phonetic implementation of the glottal stop in Garo and also examines its effect on the F0 of the adjacent vowels since it has been described as an atonal language.

An acoustic analysis of the data recorded from 8 native speakers of Garo (2 male, 6 female) shows that the glottal stop is mostly realized as a creaky voice quality on the adjacent in Garo. The glottal stop is rarely realized as a complete glottal closure. The examination of the F0 of the adjacent vowels also revealed that the presence of the glottal did not substantially lower the F0. A generalized linear mixed model that was fit to the normalized data in R (R Core Team, 2021) showed that F0 was not a significant predictor of the presence of the glottal stop (β = -0.42, SE = 2.63, p = 0.872).

The results of this paper show that the glottal stop in Garo is mostly realized as a creaky voice quality which lines up with the crosslinguistic observations. The results of this paper however, reveal that the F0 of the adjacent vowel is not affected thus potentially pointing to the fact that the glottal stop or creakiness is phonetically expresses in terms of other phonetic parameters (Keating et al., 2015).