Production and perception of question prosody in Akan

The paper presents a production experiment investigating the phonetic parameters speakers employ to differentiate Yes–No questions from string-identical statements in Akan, a West-African two-tone Kwa language. Results show that, in comparison to the statement, speakers use a higher pitch register throughout the utterance as a global parameter, and falling f0, longer duration and higher intensity as local parameters on the final syllable of the Yes–No question. Further, two perception experiments (forced-choice identification and gating) investigate the perceptual relevance of the global parameter and the local final parameters. Results show that listeners cannot assess the higher pitch register information to identify the mode of a sentence early on. Rather, identification takes place when the local phonetic parameters on the final vowel are available. The findings point to the superiority of language-specific cues in sentence mode perception. It is suggested that Akan uses a low boundary tone that associates with the right edge of the intonation phrase (L%) in Yes–No questions. The results are discussed from the point of view of question intonation typology in African languages. It is argued that a classification along the lines of functionally relevant cues is preferable to an impressionistic analysis.