The Effect of Timbre, Pitch, and Vibrato on Vocal Pitch-Matching Accuracy

The Key to Singing Off-Key: The Trained Singer and Pitch Perception Distortion

OBJECTIVES

Pitch perception distortion (PPD) is a novel term describing a phenomenon in which an amplified, accompanied singer's perception of their sung pitch relative to band or accompaniment becomes ambiguous, leading to one of two conditions: a) the singer believes they are out of tune with the accompaniment, but are in tune as perceived by a listener, or b) the singer believes they are in tune with the accompaniment, but are not. This pilot study aims to investigate the existence and incidence of PPD among amplified, accompanied performers and identify associated variables.

DESIGN/METHODS

115 singers were recruited to participate in an online survey, which collected information on musical training, performance environment, and PPD experience.

RESULTS

Reported PPD incidence was 68%, with 92% of respondents indicating that PPD occurred rarely. The factors reported as most associated with PPD experiences included loud stage volume, poor song familiarity, singing outside one's habitual pitch range, and singing loudly. Contrary to previous studies and our hypotheses, no association was found between modality of auditory feedback (e.g., in-ears versus floor monitors) and incidence of PPD. Additionally, higher levels of training were found to be associated with higher incidence of PPD.

CONCLUSIONS

The reported incidence supports that PPD exists beyond chance and anecdotal experience. In light of the highly trained sample, the data suggest that pitch accuracy in accompanied, amplified performance may be more associated with aural environment-specifically loud stage volume-and a highly trained singer's tuning strategy in response to that environment rather than a singer's mastery of vocal intonation skills in isolation. Loud stage volume was implicated as a primary factor associated with PPD, which may be related to the stapedius reflex. Future investigations will target attempted elicitation of PPD in trained singers after establishing baseline auditory reflex thresholds and objective measurements of intonation accuracy.

The Role of Vibrato in Group Singing: A Systematic Review

INTRODUCTION

Arguably one of the most controversial features of the singing voice, especially in a choral context, is the phenomenon of vibrato. Numerous pedagogical articles, mostly written by experienced choral singers or directors, discuss the importance of vibrato, sharing anecdotal insights about its control (often advocating reduction) in choral blend and vocal health.

OBJECTIVES

This systematic review aims to identify the main questions posed in the empirical study of vibrato during group singing, and how they have been addressed to date through empirical investigations.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses was employed for this review. The review team consisted of the two authors. A data extraction form was designed to capture information about the participants (including age, gender, music and singing experience), study methods, experimental procedures, outcome measures, and statistical findings.

RESULTS

Seventeen studies were included in the review and revealed that (a) relatively few empirical investigations have studied vibrato in vocal ensembles; (b) the majority focused on vibrato production rather than perception; (c) methodological approaches include Synthesis, Multi-track recordings, Stereo/Binaural recordings, and Lx/Contact recordings; and (d) the studies focused on the main themes of Adjustment, Identification, Interaction, Intonation, and Style.

CONCLUSION

With the current body of literature, it is not possible to draw general conclusions around vibrato behavior during group singing. However, the review highlights the main subareas of interest and valuable methods which have been established and through which future research can collectively shed further light on the role of vibrato in choral singing.

An Acoustic Examination of Pitch Variation in Soprano Singing

INTRODUCTION

The ability to perform acoustic inspection of data and to correlate the results with perceptual and physiological aspects facilitates vocal behavior analysis. The singing voice has specific characteristics and parameters that are involved during the phonation mechanism, which may be analyzed acoustically.

OBJECTIVE

To describe and analyze the fundamental frequency and formants in pitch variation in the /a/ vowel in sopranos.

METHODS

The sample consisted of 30 female participants between the ages of 20 to 45 years without vocal complaints. All sustained vowel sounds were recorded with the /a/ vowel sustained for 5 seconds, with three replications at low (C4-261 Hz), medium (Eb4-622 Hz), and high (Bb4-932 Hz) frequencies that were comfortable for the voice classification. In total, 90 samples were analyzed with digital extraction of the fundamental frequency (f0) and the first five formants (F1, F2, F3, F4, and F5) and manual confirmation. The middle segment was considered for analysis, whereas the onset and offset segments were not considered. Subsequently, FFT (fast Fourier transform) plots, LPC (linear predictive coding) graphs, and tube diagrams were created. The Shapiro-Wilks test was applied for adherence and the Friedman test was applied for comparison of paired samples.

RESULTS

For vocalizations at low and medium pitches, higher values were observed for the first five formant frequencies than for the f0 value. Overlaying the LPC and FFT graphs revealed a similarity between F1 and F2 at the two pitches, with clustered harmonics in the F3, F4, and F5 region in the low pitch. At the medium pitch, there was similarity between F3 and F4, an F5 peak, and tuned harmonics. However, in the high-pitch vocalizations, there was an increase in the F2, F3, F4, and F5 values in relation to f0, and there was similarity between them along with synchrony between f0 and F1, H2 and F2, H3 and F3, H4 and F4, and H5 and F5.

CONCLUSIONS

Pitch changes indicate differences in the behavior of the fundamental frequency and sound formants in sopranos. The comparison of the sustained vowels sounds in f0 at the three pitches revealed specific vocal tract changes on the LPC curve and FFT harmonics, with an extra gain range at 261 Hz, synchrony between peaks of formants and harmonics at 622 Hz, and equivalence of f0 and F1 at 932 Hz.