Landmark analysis of clear and conversational speaking styles

Abstract

Speakers appear to adjust speech production according to tradeoffs between intelligibility and economy of effort [Lindblom (1992)]. Recently, there has been much interest in investigation of differences between the clear style of speech addressed to disadvantaged listeners (non-native speakers, hearing impaired listeners, etc.) and ordinary, or conversational speaking style. Clear speech has been shown to be more intelligible across a wide range of listener types [Bradlow et al., (2002); Bradlow et al., (2003)], but the full range of parameters of variation remain undetermined. Recently also, the use of abrupt changes in the speech signal, i.e., acoustic landmarks, as an organizing principle for speech recognition has garnered attention [Espy-Wilson (2005)]. Using a landmark analysis procedure based on that of Stevens (1991) and Liu (1995), we present evidence that clear and conversational speaking styles can be distinguished in terms of the distribution of particular clusters of landmarks, corresponding very roughly to syllable-sized units. The implications of this differential distribution of landmarks across speaking styles for the organization of speech production will be discussed.