## 2 Materials and Methods
### Laboratory and Ambulatory Data Collection  
Figure 1a illustrates the laboratory setup in a sound-treated booth. The acoustic signal was recorded with a head-mounted condenser microphone positioned 15 cm from the lips (ME102, Sennheiser Electronic GmbH, Wennebostel, Germany). The laryngeal impedance signal was recorded using an electroglottograph (EG-2, Glottal Enterprises). The oral airflow and intraoral pressure signals were recorded using an aerodynamic assessment system that consisted of a pneumotachograph mask (Glottal Enterprises, Syracuse, NY, USA) and oral airflow (PT-2E, Glottal Enterprises) and intraoral pressure (PT-75, Glottal Enterprises) sensors. These signals were sampled at 20 kHz and 16-bit quantization (Digidata 1440A, Axon Instruments) following an analog antialiasing, lowpass filter stage with an 8 kHz cutoff frequency (CyberAmp Model 380, Axon Instruments, Union City, CA, USA). The neck-surface vibration signal was recorded using a miniature ACC sensor (BU-27135; Knowles Corp., Istaca, IL, USA) placed halfway between the thyroid prominence and the suprasternal notch using hypoallergenic double-sided tape (Model 2181, 3M, Maplewood, MN, USA). The ACC signal was sampled at 11,025 Hz and 16-bit quantization using an Android smartphone [53]. As described in prior work with the same study participants [42; 44; 63], each participant was asked to produced repeated /p/-vowel syllable strings from loud to soft in three vowel contexts (/pa/, /pi/, /pu/) and three pitch conditions (comfortable, higher than comfortable, and lower than comfortable). In this manner, up to 20 vowel segments could be produced in one breath; at least two trials for each vowel-pitch condition were elicited.  
Figure 1b shows the ambulatory setup. Each study participant wore the smartphone-based ambulatory voice monitor [53] for one waking day. The ACC signal was calibrated for SPL in the beginning of the day using a microphone (H1 Handy Recorder, Zoom Corporation, Tokyo, Japan) held 15 cm from the lips. Smartphone prompts instructed participants to produce /a/ vowels from loud-to-soft loudness levels. Study participants carried the smartphone in their pocket or a belt holster while they went about their activities. The smartphone application required minimal user interaction during the day with only periodic system checks activated to verify that the ACC sensor was working. Participants were instructed to pause recording of the ACC signal and remove the sensor during high-intensity exercise, swimming, or showering. After the daylong recording was complete, participants brought the voice monitoring system back to research staff to download the raw ACC signal and associated log files that included applications settings and timestamped smartphone events.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Group** & **No. Female (Male)** & **Mean (SD) Age (Years)** & **Age Range (Years)** \\ \hline PVH & 10 (0) & 29 (18) & 18–62 \\ NPVH & 7 (3) & 35 (11) & 19–64 \\ UVFP & 6 (4) & 45 (15) & 22–60 \\ Controls & 18 (8) & 31 (13) & 19–50 \\ \hline \end{tabular}  
* PVH = phonotraumatic vocal hyperfunction; NPVH = nonphonotraumatic vocal hyperfunction; UVFP = unilateral vocal fold paralysis; Controls = vocally typical control group.  
\end{table}
Table 1: Demographics of the study participants in the three patient groups and the vocally typical control group.