ISCA Archive SpeechProsody 2024
ISCA Archive SpeechProsody 2024

Prosodic grouping in Akan and the applicability of the iambic-trochaic law

Constantijn Kaland, Anjali Bhatara, Natalie Boll-Avetisyan, Thierry Nazzi

The current study investigates prosodic grouping in Akan (iso: aka), a Kwa language. Except for tone, the prosody of Akan is largely understudied. Even fewer studies have addressed the perception of prosody. The current study investigates how prosodic cues such as duration and intensity contribute to grouping in this language by a replication of a perception experiment used in earlier work. In this experiment, participants indicate whether auditory sequences are composed of repetitions of weak-strong or strong-weak sound pairs. The experiment was designed to test the predictions of the iambic-trochaic law (ITL). The ITL predicts that auditory sequences alternating in duration are grouped as iambs (weak-strong), whereas sequences alternating in intensity are grouped as trochees (strong-weak). In addition to the role of the acoustic cues of duration and intensity, the current study also tests how overall acoustic variability in the sequences affects prosodic grouping. The results for Akan show that duration differences lead to iambic grouping, as predicted by the ITL, but only when there is low acoustic variability in the sequences. No grouping effects for intensity were found. The results are interpreted and discussed in a typological context.