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.

Acoustic Measures of Voice and Physiologic Measures of Autonomic Arousal during Speech as a Function of Cognitive Load

“…Well-controlled laboratory studies are ultimately limited in their ability to characterize vocal behaviors, particularly in light of stressors. New techniques for ambulatory monitoring of voice use via neck-surface acceleration 82 when paired with ambulatory sensing of autonomic arousal may eventually allow for translation of this work to the everyday lives of speakers, including older individuals (who may respond differently to task demands) and individuals with voice disorders.…”

Continuous Authentication for Voice Assistants

“…4) If the average relative distance between glottal pulse sequence between the accelerometer and microphone segments is higher than 25%, then VAuth removes the segment from both signals. This refers to the case of interfered speech (e.g., attacker trying to inject speech); the instantaneous pitch variations should be similar between the accelerometer and microphone [33] in the absence of external interference. For example, it is evident that the pitch information is very different between the accelerometer and microphone of Fig.…”

Estimating Subglottal Pressure From Neck-Surface Acceleration During Normal Voice Production

“…Objective acoustic, aerodynamic, and electroglottographic measures are often used to better document the impact of disorders on vocal function and to help assess the effects of treatment (Hillman, Montgomery, & Zeitels, 1997;Roy et al, 2013). There is ongoing interest in obtaining measures of vocal function through the use of a small accelerometer (ACC) placed on the anterior neck surface below the larynx (subglottal) to record neck-surface vibrations as a user phonates, including estimates of aerodynamic parameters (Mehta, Van Stan, & Hillman, 2016;Wokurek & Pützer, 2009;Zañartu, Ho, Mehta, Hillman, & Wodicka, 2013). During phonation, the subglottal ACC waveform is primarily influenced by acoustic and aerodynamic energy radiating from the trachea and is minimally affected by supraglottal resonances (Wokurek & Madsack, 2011;Zañartu, Ho, et al, 2013).…”