The nonaccommodation of speech errors.
Andrea Gormley · The Journal of the Acoustical Society of America · 2009
Word-form speech errors are assumed to adapt to the unintended environment. For example, in the error ‘bads cat’ for intended ‘bad cats,’ the plural marker ‘s’ assimilates to the voicing of the ‘d’ in ‘bad.’ This phenomenon, called accommodation, provides evidence that the component responsible for errors is processed before the phonological assimilation component. Previous work on accommodation relies on the researcher to detect accommodation [D. Boomer and J. Laver, Br. J. Disord. Commun. 3, 1–12 (1968)]. Given that these studies are prone to perceptual bias, the conclusion that accommodation is the norm remains open. An acoustic analysis of errors was conducted to re-address this question. Thirty-two nonword tongue twisters, e.g., ‘tiff tivv tivv tiff,’ were designed to induce voicing errors on the coda. Because vowel lengthening before voiced codas is a phonological process in English, vowel length can be measured to detect accommodation. Errors were determined for each participant by measuring coda percent voicing and vowel duration in a control condition. Results from six participants (872 errors) show that while errors do accommodate (7.6%), nonaccommodation (40.7%) occurs more frequently. This result shows that errors do occur after phonological processing. [Work supported by OGS and Carleton University.]