Voice onset time in consonant cluster errors: can phonetic accommodation differentiate cognitive from motor errors?

Phonetic accommodation in speech errors has traditionally been used to identify the processing level at which an error has occurred. Recent studies have challenged the view that noncanonical productions may solely be due to phonetic, not phonological, processing irregularities, as previously assumed. The authors of the present study investigated the relationship between phonological and phonetic planning processes on the basis of voice onset time (VOT) behavior in consonant cluster errors.

Acoustic data from 22 German speakers were recorded while eliciting errors on sibilant-stop clusters. Analyses consider VOT duration as well as intensity and spectral properties of the sibilant.

Of all incorrect responses, 28% failed to show accommodation. Sibilant intensity and spectral properties differed from correct responses irrespective of whether VOT was accommodated.

The data overall do not allow using (a lack of) accommodation as a diagnostic as to the processing level at which an error has occurred. The data support speech production models that allow for an integrated view of phonological and phonetic processing.