Perturbation Measurements in Untrained Male Voices' Transitions From Modal to Falsetto Register

High-Speed Imaging Analysis of Register Transitions in Classically and Jazz-Trained Male Voices

“…Since then, through the use of cadaver experiments [2,3] or investigations like laryngostroboscopy [4], videokymography [5,6] and laryngoscopic high-speed imaging [7,8,9], it has been shown that certain registers are characterized by differences in vocal fold oscillation patterns. Further support for this observation has been demonstrated in electroglottographic studies for male voices [6,10,11,12,13]. The differences in vocal fold oscillation patterns are seen to be related to differences in the activity of the dominating muscle, i.e.…”

“…Instead of the typical perturbation parameter jitter, (2) relative average perturbation (RAP) was measured because it is not affected by changes in fundamental frequency [11]. RAP is a jitter measure which takes into account the period lengths ( T i - 1 , T i and T i + 1 ) of 3 consecutive oscillation cycles and determines their average perturbation according to:…”

“…It is therefore to be expected that muscle activities and/or oscillating masses have to be adjusted at the glottal level during register transitions. Since these adjustments are not easy to perform, audible register shifts can sometimes be observed in untrained subjects [11]. Furthermore, pitch jumps or major irregularities of vocal fold movements occur, presumably as a consequence of non-linear phenomena [9,15,16].…”

“…whether at the voice source level and/or from vocal tract/voice source interactions. Two recent studies [10,17] found, that for classically trained tenors, register transitions from modal to falsetto register were associated with slightly lower perturbation values, such as jitter, compared to those for untrained subjects [11]. Also, in none of the western classically trained tenors were audible pitch jumps noticed [10].…”

Perturbation of Voice Signals in Register Transitions on Sustained Frequency in Professional Tenors

“…16 On the voice source level, it was shown that for ascending register transitions from modal to falsetto register perturbation values, such as jitter, relative average perturbation (RAP), and shimmer, were increased for both untrained male voices and professional tenors. 15,17 However, while performing descending transitions, there was a lack of such an increase for frequency perturbation in the professional singer subjects. 15 Interestingly, comparable increases of frequency perturbation measures were found for transitions from modal to voix mixte function in professional tenors.…”