Using Ambulatory Voice Monitoring to Investigate Common Voice Disorders: Research Update

Many common voice disorders are chronic or recurring conditions that are likely to result from inefficient and/or abusive patterns of vocal behavior, referred to as vocal hyperfunction. The clinical management of hyperfunctional voice disorders would be greatly enhanced by the ability to monitor and quantify detrimental vocal behaviors during an individual’s activities of daily life. This paper provides an update on ongoing work that uses a miniature accelerometer on the neck surface below the larynx to collect a large set of ambulatory data on patients with hyperfunctional voice disorders (before and after treatment) and matched-control subjects. Three types of analysis approaches are being employed in an effort to identify the best set of measures for differentiating among hyperfunctional and normal patterns of vocal behavior: (1) ambulatory measures of voice use that include vocal dose and voice quality correlates, (2) aerodynamic measures based on glottal airflow estimates extracted from the accelerometer signal using subject-specific vocal system models, and (3) classification based on machine learning and pattern recognition approaches that have been used successfully in analyzing long-term recordings of other physiological signals. Preliminary results demonstrate the potential for ambulatory voice monitoring to improve the diagnosis and treatment of common hyperfunctional voice disorders

Assessments of Voice Use, Voice Quality, and Perceived Singing Voice Function Among College/University Singing Students Ages 18-24 Through Simultaneous Ambulatory Monitoring With Accelerometer and Acoustic Transducers

Previous vocal dose studies have analyzed the duration, intensity and frequency (in Hz) of voice use among college/university singing students through ambulatory monitoring. However, no ambulatory studies of this population have acquired these vocal dose data simultaneously with acoustic measures of voice quality in order to facilitate direct comparisons of voice use with voice quality during the same voicing period. The purpose of this study was to assess the voice use, voice quality, and perceived singing voice function of college/university singing students (N = 19), ages 18-24 years, enrolled in both voice lessons and choir, through (a) measurements of vocal dose and voice quality collected over 3 full days of ambulatory monitoring with an unfiltered neck accelerometer signal acquired with the Sonovox AB VoxLog portable voice analyzer collar; (b) measurements of voice quality during singing and speaking vocal tasks acquired at 3 different times of day by the VoxLog collar's acoustic and accelerometer transducers; and (c) multiple applications of the Evaluation of the Ability to Sing Easily (EASE) questionnaire about perceived singing voice function. Vocal dose metrics included phonation percentage, dose time, cycle dose, and distance dose. Voice quality measures included fundamental frequency (F0), perceived pitch (P0), dB SPL, LTAS slope, alpha ratio, dB SPL 1-3 kHz, pitch strength, shimmer, jitter, and harmonic-to-noise ratio. Major findings indicated that among these students (a) higher vocal doses correlated significantly with greater voice amplitude, more vocal clarity, and less perturbation; (b) there were significant differences in vocal dose and voice quality among non-singing, solo singing, and choral singing time periods; (c) analysis of repeated vocal tasks with the acoustic transducer showed that F0, P0, SPL, and resonance measures displayed increases from morning to afternoon to evening; (d) less perceived ability to sing easily correlated positively with higher frequency and lower amplitude when analyzing repeated vocal tasks with the acoustic transducer; and (e) the two transducers exhibited significant and irregular differences in data simultaneously obtained for 8 of the 10 measures of voice quality