The Effect of Sustained Phonation at High and Low Pitch on Vocal Jitter and Shimmer

Abstract

Looking for possible signs of vocal fatigue, acoustic waveform perturbation was measured in normal female subjects during sustained phonation at various fundamental frequencies (F_o). At none of the pitch levels a rise of the jitter or the shimmer was found after25 min of vocalization. On the other hand, an effect of F_o was seen from the start: above the habitual speaking F_o of our subjects’ voices there was a tendency for the jitter to be higher and for the shimmer to be lower.

Measuring Voice under Teachers’ Working Circumstances: F0and Perturbation Features in Maximally Sustained Phonation

“…Most teachers were from primary' school (schoolchildren aged 7-12). One was a music teacher in secondary school (schoolchildren aged [13][14][15]. and 2 subjects were teachers of English.…”

“…14], or jit ter has altered in different ways in different subjects [3]. In shimmer, a trend toward lower values has been found after loading [4], or no clear changes have been detectable [14]. Sev eral reasons can be found to explain the dis crepancy of results.…”

Factors Involved in Vocal Fatigue: A Pilot Study

“…In these studies, VF was elicited with several types of vocal loading tasks [4,5,6,7,8,9,10,11]. Results are conflicting.…”

Effect of Fasting on Voice in Women

“…Some have reported no changes and others an increase in F0. [39][40][41][42] In this study, if it was assumed that most subjects had a form of vocal fatigue while fasting, based on the aforementioned heterogeneity of this symptom and the increase in the phonatory effort observed in more that two thirds while fasting, the authors can fairly say that vocal fatigue secondary to fasting did not result in an increase in the average fundamental frequency. There were mild variations in the perturbation parameters; however, the increase in the relative average perturbation and the decrease in the shimmer were not statistically significant.…”