Magnitude of Neck-Surface Vibration as an Estimate of Subglottal Pressure During Modulations of Vocal Effort and Intensity in Healthy Speakers

Abstract

Purpose This study examined the relationship between the magnitude of neck-surface vibration (NSV Mag ; transduced with an accelerometer) and intraoral estimates of subglottal pressure (P′ sg ) during variations in vocal effort at 3 intensity levels. Method Twelve vocally healthy adults produced strings of /pɑ/ syllables in 3 vocal intensity conditions, while increasing vocal effort during each condition. Measures were made of P′ sg (estimated during stop-consonant closure), NSV Mag (measured during the following vowel), sound pressure level, and respiratory kinematics. Mixed linear regression was used to analyze the relationship between NSV Mag and P′ sg with respect to total lung volume excursion, levels of lung volume initiation and termination, airflow, laryngeal resistance, and vocal efficiency across intensity conditions. Results NSV Mag was significantly related to P′ sg ( p < .001), and there was a significant, although small, interaction between NSV Mag and intensity condition. Total lung excursion was the only additional variable contributing to predicting the NSV Mag –P′ sg relationship. Conclusions NSV Mag closely reflects P′ sg during variations of vocal effort; however, the relationship changes across different intensities in some individuals. Future research should explore additional NSV-based measures (e.g., glottal airflow features) to improve estimation accuracy during voice production.