Our research is based on the analysis of a corpus of naturally occurring conversations between pairs of native English speakers. We jointly investigate the context, syntax, and acoustic parameters (fundamental frequency, intensity and time). Data for these parameters are computed and measured by the WinPitch software (see curve below).
 

Very studies take intensity into account, i.e. the energy contained in the speech signal (in dB).

And yet, owing to certain specificities of the English language, intensity is to be considered important in our research. It is a perceptible and analyzable parameter whose linguistic functions we intend to delineate.

Our hypothesis holds that intensity, in spontaneous English speech, has an invariant linguistic function that pertains to the problem of identification. This is visible at three levels of analysis:

• identification of the lexical heart of a given word: phonological function.

• identification of the object of discourse: discursive function.

• identification of the main locutor in the conversation: interactional function.