University of Maryland, Baltimore
Subjects were fitted with an experimental dental appliance which had the effect of lowering and retracting the alveolar-palatal contour. Recordings of subjects speaking without the prosthesis and with the prosthesis at two stages of speech adaptation were analyzed acoustically and by judgmental evaluation for the effect of the appliance in disguising the voice. Individual differences were found in the type and extent of sibilant and vowel changes produced by wearing the prosthesis. Listeners made more errors on a speaker authentication task involving recordings obtained immediately after the unfamiliar prosthesis was placed in the mouth than on recordings made after a week of accommodation to the appliance, or recordings made a week apart when no prosthesis was worn.