The Influence of Bite Blocks on Perceptual and Acoustic Characteristics of Speech
N Solomon, B Munson, M Makashay
Isolating tongue movement during speech or speech-like tasks can be accomplished by placing a bite block between the molars. Previous studies have indicated that normal speakers compensate well for such perturbations to the articulators. Specific characteristics of speech vary, however, depending on the speech stimuli, bite-block size, adaptation to the bite block, and whether subjects have normal or disordered speech. In this study, 10 normally speaking young adults produced syllable repetitions and sentences loaded with lingual-alveolar consonants, high vowels, and diphthongs while gently biting on 2-mm and 5-mm bite blocks. Spoken sentences were perceived as more natural when produced without a bite block, regardless of size. Results for temporal characteristics of speech were unremarkable, with the exception that fast-syllable-repetition rate slowed as jaw opening increased. Spectral moments of sibilant frication and stop bursts differed such that mean spectral energy decreased, and diffuseness and skew increased with bite blocks. The results indicate that using a bite block detrimentally affects speech naturalness and specific spectral characteristics of certain phonemes, but that bite-block size, within a small and reasonable range, is inconsequential.