Vocal Loading-Related Changes in Male Teachers’ Voices Investigated before and after a Working Day

Abstract

Vocal loading-related changes have mainly been investigated in female voice users. The present study investigated male teachers’ voices before and after a working day. A questionnaire was used to select 22 male teachers as subjects from a larger group. Ten reported suffering often from symptoms of vocal fatigue (MC = multiple complaints group), 12 reported few vocal complaints (FC group). The subjects recorded a text reading sample at habitual loudness and loudly, and sustained vowel [a:] before and after an approximately 6-hour working day. Text samples were analyzed for total sound pressure level (SPL) and SPL at three frequency regions (50–1,000 Hz, 1–2 kHz, 2–5 kHz), fundamental frequency (F0) and alpha ratio [(SPL 1–5 kHz) – SPL (50 Hz–1 kHz)]. Jitter and shimmer were calculated from the vowel. The subjects filled in a questionnaire about vocal sensations. The MC group reported more symptoms of vocal fatigue, and the symptoms increased during the working day. F0 and SPL increased in both groups. Alpha ratio increased in the MC group but remained the same in the FC group. The MC group had higher values of jitter and shimmer. Jitter diminished in the FC group but did not change significantly in the MC group. The differences between the groups reflect either different strategies for coping with vocal loading or different loading-induced changes in the vocal organ.

Phonatory function after prolonged voice use in brazilian woman

“…Even without using aerodynamic and electromyographic measures of the larynx, the results suggest an adaptation of the laryngeal muscles for phonation, as noted by Laukkanen et al (29) . It is believed that there is an increased activity of laryngeal adductor muscles to enable the vocal production for one continuous hour, but the negative feeling caused by speech strain sounds like a warning sign to indicate the fatigue of those muscles.…”

“…Therefore, there could be an accumulation of fluid and swelling that could have been removed and balanced during the test, which may have caused the improvement in voice quality when comparing with the moments of test. On the other hand, this hypothesis would suggest that the effect caused by 1 hour of prolonged voice use could result in vocal warm-up, if not for the measurement of speech strain, which increased significantly (p=0.003), pointing to the increased effort and possible vocal fatigue, as observed in other studies (1,3,4,6,7,(10)(11)(12)(13)(14)20,28,29) . The improvement observed in vocal quality from acoustic and auditory perception measures suggests an adaptation of the laryngeal muscles to perform the requested vocal function.…”

Comparison of Vocal Vibration-Dose Measures for Potential-Damage Risk Criteria

“…Cycle-dose rate did not peak at any specific time in the middle of the day, but rose gradually and peaked in late evening hours, from 240 to 260 Hz for female teachers and from 150 to 170 Hz for male teachers. The gradual increasing trend of f 0 over the day has been reported previously (Laukkanen & Kankare, 2006) and is hypothesized to be related to lack of muscle relaxation when the larynx remains primed all day for speech. The gradual increases in f 0 during the day partially negate a reduced mean duty ratio in evening hours, making cycle-dose rate the least variable in terms of range.…”

The Effect of a Vocal Loading Task on Vocal Function Before and After 24 Hours of Thickened Liquid Use

“…The results revealed an increase in RLL-V post-vocal loading, a change that is consistent with prior reports [23][24][25]. The increase in loudness following a vocal loading task represents greater vocal fold adduction as a compensatory response to the demands of the vocal loading task and is considered to be a normal adaptive response [23,24,26].…”