Estimating Subglottal Pressure from Neck-Surface Acceleration during Normal Voice Production

• Published in: Journal of speech, language, and hearing research language, and hearing research, 2016-12, Vol.59 (6), p.1335-1345
• Main Authors: Fryd, Amanda S, Van Stan, Jarrad H, Hillman, Robert E, Mehta, Daryush D
• Format: Article
• Language: English
• Subjects: Acceleration (Education); Accelerometry - methods; Accuracy; Acoustics; Adolescent; Adult; Air Pressure; Computation; Correlation; Estimates; Female; Human Body; Human subjects; Humans; Intonation (Phonetics); Investigations; Larynx; Male; Measurement Equipment; Models, Biological; Mouth - physiology; Outcome Measures; Phonemes; Phonetics; Phonetics, Acoustic; Phonology; Physics; Physiological aspects; Physiological research; Speech; Speech Acoustics; Speech disorders; Speech production; Voice - physiology; Voice Disorders; Vowels; Young Adult
• ISSN: 1092-4388; 1558-9102
• DOI: 10.1044/2016_JSLHR-S-15-0430

Purpose: The purpose of this study was to evaluate the potential for estimating subglottal air pressure using a neck-surface accelerometer and to compare the accuracy of predicting subglottal air pressure relative to predicting acoustic sound pressure level (SPL). Method: Indirect estimates of subglottal pressure (P[subscript sg]') were obtained from 10 vocally healthy speakers during loud-to-soft repetitions of 3 different /p/-vowel gestures (/pa/, /pi/, /pu/) at 3 pitch levels in the modal register. Intraoral air pressure, neck-surface acceleration, and radiated acoustic pressure were recorded, and the root-mean-square amplitude of the acceleration signal was correlated with P[subscript sg'] and SPL. Results: The coefficient of determination between accelerometer level and P[subscript sg]' was high when data were pooled from all vowel and pitch contexts for each participant (r[superscript 2] = 0.68-0.93). These relationships were stronger than corresponding relationships between accelerometer level and SPL (r[superscript 2] = 0.46-0.81). The average 95% prediction interval for estimating P[subscript sg'] using accelerometer level was ±2.53 cm H[subscript 2]O[subscript 1] ranging from ±1.70 to ±3.74 cm H[subscript 2]O across participants. Conclusions: Accelerometer signal amplitude correlated more strongly with P[subscript sg'] than with SPL. Future work is warranted to investigate the robustness of the relationship in nonmodal voice qualities, individuals with voice disorders, and accelerometer-based ambulatory monitoring of subglottal pressure.