Singing in different performance spaces: The effect of room acoustics on vibrato and pitch inaccuracy

Does Vibrato Define Genre or Vice Versa? A Novel Parametric Approach to Vocal Vibrato Analysis

OBJECTIVES/HYPOTHESIS

A multifactorial phenomenon, vibrato exists in a variety of musical styles and genre contexts. Current vocal vibrato analysis methods using average metrics are applicable only if the vibrato is uniform, consistent, persistent, and omnipresent; features belonging predominantly to the Western Classical Opera esthetic. Historically, vocal vibrato has been analyzed with tools presuming this lens, disregarding significant stylistic characteristics of many other genres with nonnormative, naturally occurring vibrato features. Therefore, a new system of vibrato parameters considering vibrato regularity, variability, and stability over time in more genres is essential.

METHODS

Fifteen professional Operatic, Musical Theater, and Jazz mezzo-sopranos and sopranos recorded a task list of two cross-genre songs and one vocal exercise. Sixteen pitch segments from each singer were subjected to sinusoidal extraction, fo band-pass filtering, and a fast fourier transform long term average spectrum in Praat. Correlations in mean half-extent (in cents), pitch, vowel, and style/singer subject were analyzed for each sample and assessed using standard deviation, coefficient of variation (CV), linear and polynomial regression, and non-linear regression techniques in R. A subsequent perceptual survey using samples most representative of each genre's average CV was distributed to seven vocal pedagogue judges.

RESULTS

The acoustic analysis results indicated that vibrato variability predictably distinguished performed genres. The CV well-characterized vibrato variability and was higher in the samples of Musical Theater and Jazz singers. A 4-parameter logistic regression model is proposed as a novel application and more accurate representation of such multiphasic vibrato with complex shapes. The perceptual survey results confirmed that genre may be accurately distinguished and classified based on the most representative vibrato variability for each group, though Musical Theater singers' vibrato was more challenging to categorize compared with Opera and Jazz singers' vibrato.

DISCUSSION

The novel application of perceptually correlated vibrato models and time-varying parameters proposed in this two-part study may be employed to examine and evaluate complex vibrato patterns and style-specific performance. In turn, this promotes more genre-inclusive voice training in the vocal studio and contributes ecologically valid normative thresholds for vibrato habilitation and rehabilitation in the voice clinic.

A Consensus to Revise the Minimum Speech Test Battery-Version 3

PURPOSE

The Minimum Speech Test Battery (MSTB) for adults was introduced in 1996 (Nilsson et al., 1996) and subsequently updated in 2011 (Advanced-Bionics et al., 2011). The MSTB has been widely used by clinicians as a guide for cochlear implant (CI) candidacy evaluations and to document post-operative speech recognition performance. Due to changes in candidacy over the past 10 years, a revision to the MSTB was needed.

METHOD

In 2022, the Institute for Cochlear Implant Training (ICIT) recruited a panel of expert CI audiologists to update and revise the MSTB. This panel utilized a modified Delphi consensus process to revise the test battery and to improve its applicability considering recent changes in CI care.

RESULTS

This resulted in the MTSB-Version 3 (MSTB-3), which includes test protocols for identifying not only traditional CI candidates but also possible candidates for electric-acoustic stimulation and patients with single-sided deafness and asymmetric hearing loss. The MSTB-3 provides information that supplements the earlier versions of the MSTB, such as recommendations of when to refer patients for a CI, recommended patient-reported outcome measures, considerations regarding the use of cognitive screeners, and sample report templates for clinical documentation of pre- and post-operative care. Electronic versions of test stimuli, along with all the materials described above, will be available to clinicians via the ICIT website (https://www.cochlearimplanttraining.com).

CONCLUSION

The goal of the MSTB-3 is to be an evidence-based test battery that will facilitate a streamlined standard of care for adult CI candidates and recipients that will be widely used by CI clinicians.

Cognitive load associated with speaking clearly in reverberant rooms

Communication is a fundamental aspect of human interaction, yet many individuals must speak in less-than-ideal acoustic environments daily. Adapting their speech to ensure intelligibility in these varied settings can impose a significant cognitive burden. Understanding this burden on talkers has significant implications for the design of public spaces and workplace environments, as well as speaker training programs. The aim of this study was to examine how room acoustics and speaking style affect cognitive load through self-rating of mental demand and pupillometry. Nineteen adult native speakers of American English were instructed to read sentences in both casual and clear speech-a technique known to enhance intelligibility-across three levels of reverberation (0.05 s, 1.2 s, and 1.83 s at 500-1000 Hz). Our findings revealed that speaking style consistently affects the cognitive load on talkers more than room acoustics across the tested reverberation range. Specifically, pupillometry data suggested that speaking in clear speech elevates the cognitive load comparably to speaking in a room with long reverberation, challenging the conventional view of clear speech as an 'easy' strategy for improving intelligibility. These results underscore the importance of accounting for talkers' cognitive load when optimizing room acoustics and developing speech production training.

Singing in different performance spaces: The effect of room acoustics on singers' perception

Classical singers' performances vary across different acoustic environments. The changes in the delivery are influenced by the singer's perception of the venue's acoustics. This study investigated these relationships using nine professional or semi-professional classical singers. Participants performed Giordani's "Caro mio ben" aria in five venues, and the acoustic parameters reverberance (T30 and EDT), clarity (C80), early vocal support (STv), and tonal color (EDTf) were measured. From a factor analysis of the subjective analysis three major factors emerged that, we propose, would represent three generalized percepts of Room Supportiveness, Room Noiselessness, and Room Timbre. These percepts correlated significantly with objective acoustic parameters traditionally linked to vocal support, reverberation, and timbre. Room Supportiveness and Room Noiselessness significantly contributed to the singers' likability of the acoustic environment, while Room Timbre did not. This indicates that singers' perceptual preference for a performance space may be influenced by factors affecting both auditory feedback and vocal function. These findings underscore the need for performing space designers to consider the unique needs of all stakeholders, including listeners and performers. The study contributes to the bridging of the gap between subjective perceptions and objective measurements, providing valuable insights for acoustic design considerations.

Vocal Vibrato Characteristics in Historical and Contemporary Opera, Operetta, and Schlager

OBJECTIVES/HYPOTHESIS

Vibrato is a core aesthetic element in singing. It varies considerably by both genre and era. Though studied extensively in Western classical singing over the years, there is a dearth of studies on vibrato in contemporary commercial music. In addressing this research gap, the objective of this study was to find and investigate common crossover song material from the opera, operetta, and Schlager singing styles from the historical early 20th to the contemporary 21st century epochs.

STUDY DESIGN/METHODS

A total of 51 commercial recordings of two songs, "Es muss was Wunderbares sein" by Ralph Benatzky, and "Die ganze Welt ist himmelblau" by Robert Stolz, from "The White Horse Inn" ("Im weißen Rößl") were collected from opera, operetta, and Schlager singers. Each sample was annotated using Praat and analyzed in a custom Matlab- and Python-based algorithmic approach of singing voice separation and sine wave fitting novel to vibrato research.

RESULTS

With respect to vibrato rate and extent, the three most notable findings were that (1) f_o and vibrato were inherently connected; (2) Schlager, as a historical aesthetic category, has unique vibrato characteristics, with higher overall rate and lower overall extent; and (3) f_o and vibrato extent varied over time based on the historical or contemporary recording year for each genre.

CONCLUSIONS

Though these results should be interpreted with caution due to the limited sample size, conducting such acoustical analysis is relevant for voice pedagogy. This study sheds light on the complexity of vocal vibrato production physiology and acoustics while providing insight into various aesthetic choices when performing music of different genres and stylistic time periods. In the age of crossover singing training and commercially available recordings, this investigation reveals important distinctions regarding vocal vibrato across genres and eras that bear beneficial implications for singers and teachers of singing.