Effect of the glottal source and the vocal tract on the partials amplitude of vibrato in male voices

In this paper the production of vocal vibrato is investigated. The most relevant features of the acoustical vibrato signal, frequency and amplitude variations of the partials, will be related to the voice production features, glottal source GS and vocal tract response VTR . Unlike previous related works, in this approach, the effect on the amplitude variations of the partials of each one of the above-mentioned voice production features will be identified in recordings of natural singing voice. Moreover, we will take special care of the reliability of the measurements, and, to this aim, a noninteractive vibrato production model will be also proposed in order to describe the vibrato production process and, more importantly, validate the measurements carried out in natural vibrato. Based on this study, it will be shown that during a few vibrato cycles, the glottal pulse characteristics, as well as the VTR, do not significantly change, and only the fundamental frequency of the GS varies. As a result, the pitch variations can be attributed to the GS, and these variations, along with the vocal tract filtering effect, will result in frequency and amplitude variations of the acoustic signal partials.This work was supported in part by the Ministerio de Educación y Ciencia under Grant FPU, AP2000-4674. The Gobierno de Navarra and the Universidad Pública de Navarra are gratefully acknowledged for financial support

Vibrato in singing voice: the link between source-filter and sinusoidal models

The application of inverse filtering techniques for high-quality singing voice analysis/synthesis is discussed. In the context of source-filter models, inverse filtering provides a noninvasive method to extract the voice source, and thus to study voice quality. Although this approach is widely used in speech synthesis, this is not the case in singing voice. Several studies have proved that inverse filtering techniques fail in the case of singing voice, the reasons being unclear. In order to shed light on this problem, we will consider here an additional feature of singing voice, not present in speech: the vibrato. Vibrato has been traditionally studied by sinusoidal modeling. As an alternative, we will introduce here a novel noninteractive source filter model that incorporates the mechanisms of vibrato generation. This model will also allow the comparison of the results produced by inverse filtering techniques and by sinusoidal modeling, as they apply to singing voice and not to speech. In this way, the limitations of these conventional techniques, described in previous literature, will be explained. Both synthetic signals and singer recordings are used to validate and compare the techniques presented in the paper

Acoustic Measures of the Singing Voice in Secondary School Students

Descriptions of voice quality in vocal and choral music often rely on subjective terminology, which may be perceived differently between individuals. As access to software used in acoustic measurement becomes more widespread and affordable, music educators can potentially combine traditional descriptive terminology with objective acoustic descriptors and data, which may improve both teaching and singing. The secondary school choral music educator has specific challenges, in that they teach students who experience drastic physical and acoustic changes of the voice as they grow from children to adults. The purpose of this study was to objectively analyze various acoustic characteristics of the singing voice in secondary school students. In this study, secondary school students (N = 157) from three different schools who were enrolled in choir (n = 89) or instrumental music classes (n = 68) recorded voice samples singing five vowels, /i/, /e/, /a/, /o/, and /u/. Research questions investigated (a) descriptive statistics for vibrato rate, vibrato extent, singing power ratio, and amplitude differences between specific harmonic pairs; (b) differences in vibrato rate and extent between students enrolled in choir and students not enrolled in choir; (c) between-subjects and within-subjects comparisons in singing power ratio (SPR) between singers based on choir enrollment and voice part for five different vowel productions; and (d) between-subjects and within-subjects comparisons for differences in amplitude between specific harmonics between singers based on choir enrollment and voice part for five different vowel productions. Vibrato rate (M = 4.58 Hz, SD = 1.45 Hz ), vibrato extent (M = 1.45% or 25 cents, SD = 0.86% or 15 cents), and SPR (M = 24.67 dB, SD = 10 dB), and various amplitude differences were not different between students enrolled in choir and students not enrolled in choir. There were significant within-subjects differences for singers by vowel, as well as significant within-subjects interactions for vowel and voice part with SPR and amplitude differences between harmonic pairs. There were also significant differences between voice parts for amplitude difference between harmonic pairs. Implications for choral music educators and suggestions for further research based on these findings were discussed in Chapter 5

Respiration in operatic singing: Intention to communicate

Professional operatic singing can be performed technically for practice and rehearsal, or with heightened emotion through intention to communicate with an audience. Previous studies of respiration in operatic singing have not taken into account the professional performer's ability to differentiate at will between rehearsal and performance modes of singing. The aim of this thesis is to investigate the differences between singing 'with intention to communicate' (as if performing) and singing 'technically' (as if in rehearsal). The hypothesis is that this specified change of condition would change the respiratory patterns employed by the singers. Estimation of respiratory patterns was obtained using magnetometers. Performance singing was labelled 'IC' (intention to communicate). Rehearsal singing was labelled 'T' (technical) and also included 'TL' (technical loud) and 'TS' (technical soft). Each of the five singers performed two tasks (a free choice aria in Italian, and a set song). Only intra-subject analysis was used. One thousand and one breaths were analysed. These were then matched, so that only complete musical phrases (sung six times by the same singer) were compared with each other. Seven hundred and sixty-two matched phrases were analysed in this way. Measured variables were initiation lung volume (ILV), termination lung volume (TLV), the amount of lung volume expired (LVE), %VC released per second (Flow), the expiratory time (Te), and inspiratory time (Ti). Sound pressure level (SPL) was measured. This study also examined the ability of experienced listeners to distinguish between the T and IC performances from DAT recordings. Findings show that in comparison with T singing, IC singing used more air, with a greater percentage of vital capacity expired per second, but without a simple association with sound pressure level or expiratory time. Listeners were able to distinguish IC from T performances, demonstrating a perceived difference in the quality of the vocal output. These results demonstrate that performance intention to communicate, compared to rehearsal, results in a measurable difference in respiratory parameters, and therefore needs to be specified in future research

Tuning Your Choral Pipes: An Organist's Manual for Choral Sound

As choir masters, many organists have the responsibility of hiring and working with paid singers as well as a dedicated group of volunteer singers ranging in experience from novice to advanced. The similarities of the human voice to the pipe-organ are numerous. Using these similarities and scientific analysis of the two instruments, organists can familiarize themselves with the tuning system of the human voice. Like the pipe organ, the human voice is capable of wide variety of sounds, qualities, textures, pitches and levels of volume. Unlike an organ pipe, the voice is not a fixed resonator. The voice is the most flexible of all musical instruments. Instructing an ensemble of singers to shape their sound simultaneously is the beginning of “tuning your choral pipes.” It will be important to establish terminology with your singers in order to successfully communicate with them despite their varying levels of ability and pronunciation differences. Becoming familiar with the mechanics of the voice and an alphabet of pure vowel sounds can help organist-choir masters achieve a greater degree of success when working with singers. The stops, pipes and expression pedal of the human voice are defined by the laryngeal muscles as they relate to registration, the vocal tract shape as defined by the vowel, and the amount of volume created by the air pressure. This guide for organists covers these topics and contains exercises for the reader to apply during choral rehearsals

Relationship of the cricothyroid space with vocal range in female singers

It is well documented that the cricothyroid (CT) space opens and closes with changes in pitch, narrowing with rising pitch and widening with falling pitch. Indeed, cricothyroid approximation surgery, a procedure where the CT space is deliberately made smaller, is used in male to female transgender subjects to successfully elevate vocal pitch. The present study focuses on investigating the relationship between the anterior CT space at rest and vocal range in female singers. Laryngeal dimensions (anterior CT space and heights of the thyroid and cricoid cartilages) were measured using ultrasound in 43 healthy, classically trained, female singers. Potential associations with and between age, ethnicity, anthropometric indices (height, weight, body mass index), neck dimensions (circumference and length), vocal data (practice and performance vocal range, lowest and highest practice and performance notes) along with usual speaking fundamental frequency were also explored. The main finding was that mezzo-sopranos have a significantly wider resting CT space than sopranos (11.6 mm versus 10.4 mm; P=0.007). Mezzo-sopranos also had significantly lower ‘lowest and highest’ performance notes and speaking fundamental frequencies than sopranos. Furthermore, there was a weak but significant negative correlation between the magnitude of the anterior CT space and the lowest performance note (r=-0.448; P=0.003) but there was no significant correlation with either the highest performance note or vocal range. These results suggest there is a relationship between the CT space and the lowest note a female can sing. This was evident in the correlation of a small CT space with a higher ‘lowest performance note’. It appears that the CT space influences how low female singers can sing, but not how high they can sing