###### Abstract  
The aerodynamic voice assessment of subglottal air pressure can discriminate between speakers with typical voices from patients with voice disorders, with further evidence validating subglottal pressure as a clinical outcome measure. Although estimating subglottal pressure during phonation is an important component of a standard voice assessment, current methods for estimating subglottal pressure rely on non-natural speech tasks in a clinical or laboratory setting. This study reports on the validation of a method for subglottal pressure estimation in individuals with and without voice disorders that can be translated to connected speech to enable the monitoring of vocal function and behavior in real-world settings. During a laboratory calibration session, a participant-specific multiple regression model was derived to estimate subglottal pressure from a neck-surface vibration signal that can be recorded during natural speech production. The model was derived for vocally typical individuals and patients diagnosed with phonotraumatic vocal fold lesions, primary muscle tension dysphornia, and unilateral vocal fold paralysis. Estimates of subglottal pressure using the developed method exhibited significantly lower error than alternative methods in the literature, with average errors ranging from 1.13 to 2.08 cm H\({}_{2}\)O for the participant groups. The model was then applied during activities of daily living, thus yielding ambulatory estimates of subglottal pressure for the first time in these populations. Results point to the feasibility and potential of real-time monitoring of subglottal pressure during an individual's daily life for the prevention, assessment, and treatment of voice disorders.  
subglottal pressure; clinical voice assessment; neck-surface accelerometer; ambulatory voice monitoring +
Footnote †: journal: Accepted: 18 October 2022  
complaint at some point in their lives [1; 2]. The impact of living with a voice disorder is far-reaching, often exacting significant financial, social, professional, and psychological consequences [3]. The societal burden of voice disorders has been estimated to reach up to USD 13.5 billion dollars each year due to work-related disability, lost productivity, and healthcare costs [3; 4; 5]. Individuals with voice disorders often suffer from heightened sensations of vocal effort and fatigue while speaking, which are typically attributed to inefficient vocal function and behavior [6; 7; 8]. Thus, there is a strong clinical motivation for the objective measurement of acoustic and aerodynamic parameters related to vocal efficiency that can provide a window into the daily life of these individuals.  
Subglottal air pressure (Ps) during voice production has been linked with the self-perception of vocal effort [9; 10; 11] and is an important part of objective measures of vocal efficiency [12; 13; 14; 15; 16]. A positive aerodynamic pressure gradient across the glottis facilitates self-sustained oscillation of the vocal folds. This oscillation modulates the laryngeal airflow from the lungs and provides energy excitation to the vocal tract to output what we measure and perceive auditorily as the acoustic voice signal. Ps plays an important part in vocal function and aids in controlling onset, offset, intensity, and fundamental frequency (\(f_{\text{o}}\)) [17; 18; 19; 20]. Measures of Ps and measures derived from Ps and laryngeal airflow measures (such as laryngeal resistance and vocal efficiency measures) can discriminate patients with voice disorders from individuals with typical voices and discriminate vocal characteristics before and after the clinical management of a voice disorder [21; 22; 23; 24; 25; 26; 27; 28]. The efficiency with which aerodynamic power is transferred into acoustic power can be an indicator of vocal health [29].