Prosodic comparison of declarative and interrogative utterances in Standard Colloquial Bangla

This paper presents a comparative study of prosodic features of utterances of two types of Bangla sentences: the declarative type and the interrogative (`yes-no´ question) type whose textual contents are identical except for the punctuation marks in Bangla. The study is based on the analysis of 44 utterances each of the declarative type and the interrogative type spoken by native speakers of Standard Colloquial Bangla (SCB). The results of F₀ contour analysis show that declarative utterances have a gradually falling F₀ contour with a terminal fall whereas interrogative utterances have a rising contour and a terminal rise. It is also observed that interrogative utterances have a positive swing of F₀ larger than that of declarative utterances, and the maximum of F₀ occurs within the prosodic word containing the interrogative information. It is shown that these differences can be represented in terms of differences in parameters of the F₀ contour command-response model. The validity of the analysis was confirmed by perceptual experiments using synthetic stimuli, demonstrating the feasibility of the command-response model in speech synthesis of Bangla.