Wivine Decoster

Longitudinal voice changes: facts and interpretation.

To study intraindividual vocal changes over time, a longitudinal research design is preferred. However, this procedure reveals many restrictions concerning methodology and interpretation, especially in cases of (semi)retrospective studies. This is illustrated by an investigation of the voices of 20 male Dutch-speaking reporters of the Belgian Radio Broadcasting service. These men read the same text they did 30 years previously for a digital registration. After having copied the high-quality archival recordings digitally, the results of the acoustical analysis of both recordings (recent and archival) were compared. This was done to search for the contribution of aging. In this article we report on the results of the speaking fundamental frequency (SFF) and the standard deviation of the SFF (SFFsd) as a measure of intraindividual variability, and the voice onset time (VOT). Results indicate that, in connected speech, SFF decreased, SFFsd became more restricted, and the VOT increased strongly. The interpretation of the results compels us to conclude that it is extremely difficult to define the specific effect of aging alone, since it is only one element among many others, including methodological concerns.

Physical Therapy as a Means to Optimize Posture and Voice Parameters in Student Classical Singers: A Case Report

OBJECTIVES/HYPOTHESIS This study aimed at reporting on an intervention for optimizing postural alignment and voice parameters. STUDY DESIGN Case report. METHODS A clinical examination, including an evaluation of postural alignment, was performed and several voice parameters were investigated before, during, and after an individual rehabilitation program aimed at optimizing joint mobility, muscular stability, and posture. This program was given to a 26-year-old female classical singing student. RESULTS After a nine-session intervention (4 months), postural alignment was improved. The patient showed a good breath support and was able to maintain the lateral dimensions of the thorax, except for the high tones. Furthermore, she had a normalized cervical and scapulothoracic stability. At the last session, she had a lack of relaxation of the masseter muscle while singing. The vocal dynamic and pitch range were extended with smoother curves connecting the measuring points of the maximal and minimal vocal intensity, measured by means of the voice range profile. CONCLUSIONS Results show that, in this student singer, postural alignment could be changed within 4 months and that it could influence some voice parameters. Further research in larger samples is necessary to see whether these findings can be generalized to other singers.

Speaking fundamental frequency in monozygotic and dizygotic twins

The speaking fundamental frequency (SFF) and the intraindividual variation of the SFF during the reading of a Dutch standard text were measured in 30 female monozygotic twins (MT) and 30 dizygotic twins (DT), aged 15-29 years. A control group was created that consisted of 30 nonrelated paired individuals of equal age. Studying the intrapair correlation coefficients it seemed that the SFF was similar to a greater degree in MT and to a lesser degree in DT, while there was no correlation at all in nonrelated peers. These results are compatible with a genetic basis for the SFF. On the other hand, the intraindividual variation of the SFF was highly similar in MT and in DT (but not in nonrelated peers), so that for this parameter it was not possible to discern the influences of genetic disposition and shared environment.

Changes in spectral measures and voice-onset time with age: a cross-sectional and a longitudinal study

In this study, we searched for changes in spectral features (during the sustained vowels [a] and [i]) and the voice onset time (VOT, of [pa] and [ka]) of the ageing voice. A longitudinal study (on 20 participants) and a cross-sectional study (on 265 participants) were conducted. The spectral parameters under consideration were: the difference in amplitude between the first and the second harmonic, the energy difference between the frequency band below 1 kHz and 2-4 kHz, and the energy difference between < 1 kHz and 4-5 kHz. The VOT was also measured. Comparing five age bands of men and women, the cross-sectional study revealed a stronger H2 relative to H1 for women above 60 years pronouncing both vowels [a] and [i]. A relatively stronger spectral level was found between 4 and 5 kHz in elderly men and women (60+) for [i] compared to young men and women (20-29 years). Significant differences in the longitudinal study were not identical to those of the cross-sectional study. After a time interval of 30 years, 20 men produced a relatively weaker 2- to 4-kHz part of the spectrum and the VOT became much longer. It was impossible to attribute the changes purely to the process of ageing. Situations and emotions also play an important role and contribute to the different findings of the two groups of participants under consideration.

Acoustic differences between sustained vowels perceived as young or old

Perceptual recognition of young and old voices was studied with vowels uttered by male and female speakers. In the specific test conditions of this study more than 90% of the judgements were correct, even when only the centre part of a sustained vowel was heard. The latter thus contains relevant information for age discrimination. The sustained phonations that were unanimously judged as young or old by all the listeners were acoustically analysed. It appeared that several parameters were significantly different and consequently may have played a role in the perceptual judgement of young versus old: changes in fundamental frequency, higher perturbation measures, lower H1-H2 ratio in women, and lower formant frequencies. The lower F2 was, statistically, the most significant result. On the other hand, for none of the measures did the differences between young and old go in the same direction in all the correctly judged voices. Each parameter showed differences in both senses whereas the age recognition was u...

A lifetime of professional singing: Voice parameters and age in the Netherlands Radio Choir.

Abstract In professional choirs one would like to identify the incidence and severity of vocal problems due to ageing, and know how to influence them. The aim of the current study was to investigate to what extent easily obtainable voice parameters were age-related. From 47 singers of the Netherlands Radio Choir the Voice Range Profile parameters and the vibrato characteristics were measured. Dysphonia Severity Index (DSI) was calculated. We found that the age of male and female singers correlated negatively to the highest fundamental frequency and the Dysphonia Severity Index. No signs of slower and wider vibrato were found. These findings can lead to identifying adequate parameters e.g. for the ageing voice, useful in larger groups of professional singers.

Great talent, excellent voices—no problem for pubertal girls?

This research on 17 girls (aged 9;9 y to 16;11 y) singing in an established choir was focused on two issues: 1) the variety in physical and vocal development using Gackles model, and 2) the matching of vocal demands and abilities. Developmental and acoustical data on the speaking and singing voice revealed considerable variation between individual girl singers. The model was greatly applicable. However, all girls had a greater total singing range, mainly in favour of the lower tones, and 11 girls used a lower speaking fundamental frequency. A third of the girls met the vocal and developmental features of their stage at a younger age. Next the lower limit of the frequency range of all girls was several semitones below the lowest notes of the pieces being worked on at the time of the experiment. However the upper limit of the pieces coincided with or exceeded their upper frequency limit.

Discrimination of Three Basic Female Voice Types in Female Singing Students by Voice Range Profile-Derived Parameters

Aims: To assess whether individual parameters or combinations of voice range profile parameters (also called ‘features’) are able to yield a clear cluster separation with which three basic female voice categories can be discriminated and can provide a basis for settling the issue of voice classification. Methods: The voice range profiles of 206 female conservatory singing students were recorded, parameterized into more compact descriptions (‘features’), and subjected to a cluster analysis. Results: The three-cluster case provided the most consistent solution across all feature combinations. The feature that led to the best cluster separation was the ratio of the perimeter length of the chest voice part of the voice range profile versus the total perimeter length. Conclusions: Based on a statistical analysis of voice range profile parameters, the ratio of the perimeter length of the chest voice versus the total perimeter length was shown to yield a clear separation into three basic female voice types, which in turn may give us a basis for settling the issue of voice classification.

Stable Voice Clusters Identified When Using the Maximum versus Minimum Intensity Curve in the Phonetogram.

Objective: To examine whether the minimum as well as the maximum voice intensity (i.e. sound pressure level, SPL) curves of a voice range profile (VRP) are required when discovering different voice groups based on a clustering analysis. In this approach, no a priori labeling of voice types is used. Patients and Methods: VRPs of 194 (84 male and 110 female) professional singers were registered and processed. Cluster analysis was performed with the use of features related to (1) both the maximum and minimum SPL curves and (2) the maximum SPL curve only. Results: Features related to the maximum as well as the minimum SPL curves showed three clusters in both male and female voices. These clusters, or voice groups, are based on voice types with similar VRP features. However, when using features related only to the maximum SPL curve, the clusters became less obvious. Conclusion: Features related to the maximum and minimum SPL curves of a VRP are both needed in order to identify the three voice clusters.