Some Effects of Tactile and Auditory Alterations on Speech Output

Abstract

This investigation studied the effects on articulation, duration, average peak level, and fundamental frequency of speech demonstrated by normal subjects when oral region tactile and/or auditory sensory information is altered. Thirteen female subjects read a standard passage under the following six conditions: (a) control; (b) binaural masking; (c) topical anesthetization of the oral region by application of Xylocaine HCl 4%; (d) local anesthetization of the oral region by bilateral mandibular and infra-orbital nerve block techniques employing Xylocaine HCL 2%; (e) simultaneous administration of conditions b and c; (f) simultaneous administration of conditions b and d. Recorded speech samples for all conditions were subjected to analysis by use of a high speed level recorder, a phonation timer, and an oscillographic technique. The speech samples were also analyzed for articulatory deviations by a panel of judges. Statistical analysis of the data indicated that significant alterations in average peak level, articulation, and rate variability occur under conditions of altered tactile sensation. Similar trends were also noted for the mean syllable duration and phonation/time ratio variables. In addition it was found that the effects of multiple sensory disturbances are cumulative in nature for certain speech output variables.