Prosodic realization and interpretation of English

Imperative clauses can communicate a number of speech acts, and differences in intonation have been argued to prompt different interpretations. So far, however, limited phonetic evidence has been presented for such proposals. The focus in the current work is on maximally strong imperatives (commands) and weaker imperatives (mainly involving advice) in English. We report on a series of phonetic experiments intended to address whether listeners reliably associate stronger and weaker imperatives with idealized intonation (Experiment 1) and whether speakers produce these two types of imperatives differently (Experiment 2). Individual variability in our production data led us to test whether listeners can map the variable pronunciation patterns found in Experiment 2 to stronger and weaker imperatives (Experiment 3), as they did with the idealized pronunciations in Experiment 1. Despite substantial cross-talker intonation variation, listeners' stronger/weaker imperative recognition performance paralleled accuracy with the idealized productions. Analysis of the whole utterances indicates that speech rate and global pitch setting work along with the final intonation contour to signal semantic meaning in English imperatives. These results suggest that the mapping between meaning and form is complex and involves redundancy.