title: Relationships between vocal function measures derived from an acoustic microphone and a subglottal neck-surface accelerometer.
abstract: Monitoring subglottal neck-surface acceleration has received renewed attention due to the ability of low-profile accelerometers to confidentially and noninvasively track properties related to normal and disordered voice characteristics and behavior. This study investigated the ability of subglottal neck-surface acceleration to yield vocal function measures traditionally derived from the acoustic voice signal and help guide the development of clinically functional accelerometer-based measures from a physiological perspective. Results are reported for 82 adult speakers with voice disorders and 52 adult speakers with normal voices who produced the sustained vowels /a/, /i/, and /u/ at a comfortable pitch and loudness during the simultaneous recording of radiated acoustic pressure and subglottal neck-surface acceleration. As expected, timing-related measures of jitter exhibited the strongest correlation between acoustic and neck-surface acceleration waveforms (r≤ 0.99), whereas amplitude-based measures of shimmer correlated less strongly (r≤ 0.74). Additionally, weaker correlations were exhibited by spectral measures of harmonics-to-noise ratio (r≤ 0.69) and tilt (r≤ 0.57), whereas the cepstral peak prominence correlated more strongly (r≤ 0.90). These empirical relationships provide evidence to support the use of accelerometers as effective complements to acoustic recordings in the assessment and monitoring of vocal function in the laboratory, clinic, and during an individual's daily activities.
authors.affiliation: Center for Laryngeal Surgery & Voice Rehabilitation, Massachusetts General Hospital, Boston MA 02114 USA, Department of Surgery, Harvard Medical School, Boston, MA 02115 USA, and the Institute of Health Professions, Massachusetts General Hospital, Boston, Massachusetts 02129 USA ( mehta.daryush@mgh.harvard.edu ).
authors.forename: Daryush D
authors.initials: DD
authors.lastname: Mehta
authors.affiliation: Center for Laryngeal Surgery & Voice Rehabilitation, Massachusetts General Hospital, Boston MA 02114 USA and the Institute of Health Professions, Massachusetts General Hospital, Boston, Massachusetts 02129 USA ( jvanstan@mghihp.edu ).
authors.forename: Jarrad H
authors.initials: JH
authors.lastname: Van Stan
authors.affiliation: Center for Laryngeal Surgery & Voice Rehabilitation and Institute of Health Professions, Massachusetts General Hospital, Boston MA 02114 USA and Surgery and Health Sciences & Technology, Harvard Medical School, Boston, MA 02115 ( hillman.robert@mgh.harvard.edu ).
authors.forename: Robert E
authors.initials: RE
authors.lastname: Hillman
keywords: ambulatory voice monitoring; cepstral peak prominence; harmonics-to-noise ratio; neck-surface accelerometer; vocal function analysis; vocal perturbation