[Formant structures of vowels produced in stutterers' speech in normal and fast speech rates]

The aim of this study is to analyse the steady-state portion of the first two formants (F1 and F2) in the production of [CVp] sequences, containing vowels [i, a, u] pronounced in two speech rates (normal and fast), by groups of untreated and treated stutterers, and control subjects.

We recorded 15 speakers (5 control speakers, 5 non-treated stutterers and 5 treated stutterers) who had to repeat sentences containing [CV] sequences ten times, in normal and fast speech rates, where [C] was [p], [t] or [k] and [V], [i], [a] or [u].

Comparing data between the three groups of speakers, a vowel space reduction is observed for stutterers at a normal speaking rate, compared with control speakers and treated stutterers. When speech rate increases, no reduction of vowel space is noticeable for non-treated stutterers, contrary to treated stutterers and controls.

Results for stutterers could be interpreted in terms of lack of articulatory flexibility.