Articulation and Stress/Juncture Production Under Oral Anesthetization and Masking

Abstract

Eight subjects, half of them naive and the other half aware of the purpose of the experiment, spoke 30 pairs of sentences involving the production of intricate stress/juncture patterns along with a passage containing all major consonant phonemes in English in various intraword positions. All subjects spoke all materials under: (1) normal conditions, (2) 110 dB re: 0.0002 ubar white noise masking, (3) extensive local anesthesia of the oral cavity, and (4) masking and anesthesia combined. Stress and juncture patterns were correctly produced despite all feedback disruption, and there was no difference between naive and aware subjects. Noise masking produced a decline in speech quality and a disruption of normal rhythm, both of which were even more seriously affected by anesthesia and anesthesia plus masking. There were no significant vowel misarticulations under any condition, but there was nearly a 20% rate of consonant misartiqulation under anesthesia and anesthesia and noise. Mis-articulation was most severe for fricatives and affricates in the labial and alveolar regions, presumably because these productions demand a high degree of precision of articulate shape and location and hence, intact feedback. Results are discussed in terms of feedback-control mechanisms for speech production.