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Purpose: The purpose of this study was to examine laryngeal and respiratory physiological changes in teachers before and after a 1-hour vocal loading challenge., Methods: Twelve teachers completed ratings of vocal tiredness, vocal effort, and produced a reading passage and monologue before and after a 1-hour vocal loading challenge (reading aloud in noise). Sound pressure level, lung volume parameters, cepstral peak prominence, and low/high spectral ratio were measured., Results: After loading, participants significantly increased vocal effort, vocal tiredness, utterance length, and sound pressure level, and significantly decreased % vital capacity/syllable., Conclusions: Following the 1-hour reading-aloud challenge, tiredness and effort increased. However, lung volume did not change and cepstral peak prominence and low/high spectral ratio remained in the normal range. Future studies are needed to understand the effect of vocal use and vocal loading in teachers., (Copyright © 2019 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: Individuals with Parkinson's disease (PD) exhibit differences in displacement and velocity of the articulators as compared with older adults. The purpose of the current study was to examine effects of 3 loudness cues on articulatory movement patterns in individuals with PD., Method: Nine individuals diagnosed with idiopathic PD and 9 age- and sex-matched healthy controls produced sentences in 4 conditions: (a) comfortable loudness, (b) targeting 10 dB above comfortable, (c) twice as loud as comfortable, and (d) in background noise. Lip and jaw kinematics and acoustic measurements were obtained., Results: Both groups significantly increased sound pressure level (SPL) in the loud conditions as compared with the comfortable condition. For the loud conditions, both groups had the highest SPL in the background noise and the 10 dB conditions, and the lowest SPL in the twice as loud condition. Control participants produced the largest opening displacement in the background noise condition and the smallest opening displacement in the twice as loud condition. Conversely, individuals with PD produced the largest opening displacement in the twice as loud condition and the smallest opening displacement in the background noise condition., Conclusions: Control participants and individuals with PD responded to cues to increase loudness in different ways. Changes in SPL may explain differences in kinematics for the control participants, but they do not explain such differences for individuals with PD.

Purpose: The purpose of the present investigation was to examine acoustic voice changes across the life span. Previous voice production investigations used small numbers of participants, had limited age ranges, and produced contradictory results., Method: Voice recordings were made from 192 male and female participants 4-93 years of age. Acoustic measures of fundamental frequency (F0), sound pressure level (SPL), and signal-to-noise ratio (SNR) were made. Coefficients of variation for F0, SPL, and SNR served as measures of variability. Variables were analyzed separately with stepwise regressions, using age and sex as predictors., Results: Differences in F0 and SNR across the life span were sex specific. Male and female participants demonstrated significant nonlinear trends for F0, but the trends were stronger for male participants. Female participants demonstrated a similar nonlinear trend for SNR, whereas male participants demonstrated linear increases in SNR with age. Variability of F0, SPL, and SNR followed nonlinear trends, higher at younger and older ages., Conclusions: Changes in voice production occur throughout the life span, often in a nonlinear way and differently for male and female individuals. Higher variability of acoustic measures of voice in both young and old speakers reflects changes in anatomic structure, physiologic mechanisms, and motor control.

Individuals with Parkinson's disease (PD) demonstrate low vocal intensity (hypophonia) which results in reduced speech intelligibility. We examined the effects of three cues to increase loudness on respiratory support in individuals with PD. Kinematic data from the rib cage and abdomen were collected using respiratory plethysmography while participants read a short passage. Individuals with PD and normal age- and sex-matched controls (OC) increased sound pressure level (SPL) to a similar extent. As compared to OC, individuals with PD used larger rib cage volume excursions in all conditions. Further, they did not slow their rate of speech in noise as OC speakers did. Respiratory strategies used to support increased loudness varied with the cue, but the two groups did not differ in the strategies used. When asked to target a specific loudness, both groups used more abdominal effort than at comfortable loudness. Speaking in background noise resulted in the largest increase in SPL with the most efficient respiratory patterns, suggesting that natural or implicit cues may be best when treating hypophonia in individuals with PD. Data demonstrate the possibility that both vocal loudness and speech rate are impacted by cognitive mechanisms (attention or self-perception) in individuals with PD.

One of the most important areas of study in speech motor control is the identification of control variables, the variables controlled by the nervous system during motor tasks. The current study examined two hypotheses regarding control variables in speech production: (1) pressure and resistance in the vocal tract are controlled, and (2) perceptual and acoustic accuracy are controlled. Aerodynamic and acoustic data were collected on 20 subjects in three conditions, normally (NT), with an open air pressure bleed tube in place (TWB), and with a closed bleed tube in place (TNB). The voice recordings collected from the speakers in the production study were used in the perceptual study. Results showed that oral pressure (Po) was significantly lower in the TWB condition than in the NT and TNB conditions. The Po in the TWB condition seemed to be related to maintenance of subglottal pressure (Ps). Examination of the perceptual and acoustic data indicated that perceptual accuracy for [a] was achieved by maintaining Ps to preserve a steady sound pressure level, fundamental frequency, and voicing. Overall, it appeared speakers controlled pressure in compensating, but for the ultimate goal of maintaining acoustic and perceptual accuracy.