An exploration of skin acceleration level as a measure of phonatory function in singing.

Two kinds of fluctuations are observed in phonetogram recordings of singing. Sound pressure level (SPL) can vary due to vibrato and also due to the effect of open and closed vowels. Since vowel variation is mostly a consequence of vocal tract modification and is not directly related to phonatory function, it could be helpful to suppress such variation when studying phonation. Skin acceleration level (SAL), measured at the jugular notch and on the sternum, might be less influenced by effects of the vocal tract. It is explored in this study as an alternative measure to SPL. Five female singers sang vowel series on selected pitches and in different tasks. Recorded data were used to investigate two null hypotheses: (1) SPL and SAL are equally influenced by vowel variation and (2) SPL and SAL are equally correlated to subglottal pressure (P(S)). Interestingly, the vowel variation effect was small in both SPL and SAL. Furthermore, in comparison to SPL, SAL correlated weakly to P(S). SAL exhibited practically no dependence on fundamental frequency, rather, its major determinant was the musical dynamic. This results in a non-sloping, square-like phonetogram contour. These outcomes show that SAL potentially can facilitate phonetographic analysis of the singing voice.

Fourier descriptor analysis and unification of voice range profile contours: method and applications.

PURPOSE: To describe a method for unified description, statistical modeling, and comparison of voice range profile (VRP) contours, even from diverse sources. METHOD: A morphologic modeling technique, which is based on Fourier descriptors (FDs), is applied to the VRP contour. The technique, which essentially involves resampling of the curve of the contour, is assessed and also is compared to density-based VRP averaging methods that use the overlap count. RESULTS: VRP contours can be usefully described and compared using FDs. The method also permits the visualization of the local covariation along the contour average. For example, the FD-based analysis shows that the population variance for ensembles of VRP contours is usually smallest at the upper left part of the VRP. To illustrate the method's advantages and possible further application, graphs are given that compare the averaged contours from different authors and recording devices--for normal, trained, and untrained male and female voices as well as for child voices. CONCLUSIONS: The proposed technique allows any VRP shape to be brought to the same uniform base. On this uniform base, VRP contours or contour elements coming from a variety of sources may be placed within the same graph for comparison and for statistical analysis.

The singer's voice range profile: female professional opera soloists.

This work concerns the collection of 30 voice range profiles (VRPs) of female operatic voice. We address the questions: Is there a need for a singer's protocol in VRP acquisition? Are physiological measurements sufficient or should the measurement of performance capabilities also be included? Can we address the female singing voice in general or is there a case for categorizing voices when studying phonetographic data? Subjects performed a series of structured tasks involving both standard speech voice protocols and additional singing tasks. Singers also completed an extensive questionnaire. Physiological VRPs differ from performance VRPs. Two new VRP metrics, the voice area above a defined level threshold and the dynamic range independent from the fundamental frequency (F(0)), were found to be useful in the analysis of singer VRPs. Task design had no effect on performance VRP outcomes. Voice category differences were mainly attributable to phonation frequency-based information. Results support the clinical importance of addressing the vocal instrument as it is used in performance. Equally important is the elaboration of a protocol suitable for the singing voice. The given context and instructions can be more important than task design for performance VRPs. Yet, for physiological VRP recordings, task design remains critical. Both types of VRPs are suggested for a singer's voice evaluation.

The Swedish version of the Voice Handicap Index adapted for singers.

This study evaluates a Swedish version of the Voice Handicap Index adapted for singers. A total of 96 healthy singers and 30 singer-patients completed the questionnaire. Validity and reliability, internal coherence, and group differences were assessed. The singer-patient group had significantly higher scores than the control group. Reliability was confirmed by high Cronbach's (>0.78) for test-retest scores, and for each of the sub-scales. Test-retest stability in both groups was confirmed by high correlation values alpha (>0.8). Overall scores compared closely to those from previous reports. The Swedish translation of the adapted VHI for singers (RHI-s) is valid and reliable and shows sensitivity to the singer's concerns. It can be considered a useful tool in the clinical assessment of Swedish healthy or pathological singers.

Not just sound: supplementing the voice range profile with the singer's own perceptions of vocal challenges.

A commercial phonetograph was complemented with a response button, such that presses resulted in marked regions in the voice range profile (VRP). This study reports the VRP data of 16 healthy female professionally trained singers (7 mezzo-sopranos and 9 sopranos). Subjects pressed the button to indicate sensations of vocal instability or reduced control during phonation. Each press thereby marked potential areas of difficulty. A method is presented to quantify the consistency of button use for repeated tasks. The pattern of button presses was significantly consistent within subjects. As expected, the singers pressed at the extremes of VRP contours as well as at register transitions. These results and the potential of the method for the assessment of vocal problems of singers are discussed.