Vocal fry may undermine the success of young women in the labor market

No evidence that averaging voices influences attractiveness

Vocal attractiveness influences important social outcomes. While most research on the acoustic parameters that influence vocal attractiveness has focused on the possible roles of sexually dimorphic characteristics of voices, such as fundamental frequency (i.e., pitch) and formant frequencies (i.e., a correlate of body size), other work has reported that increasing vocal averageness increases attractiveness. Here we investigated the roles these three characteristics play in judgments of the attractiveness of male and female voices. In Study 1, we found that increasing vocal averageness significantly decreased distinctiveness ratings, demonstrating that participants could detect manipulations of vocal averageness in this stimulus set and using this testing paradigm. However, in Study 2, we found no evidence that increasing averageness significantly increased attractiveness ratings of voices. In Study 3, we found that fundamental frequency was negatively correlated with male vocal attractiveness and positively correlated with female vocal attractiveness. By contrast with these results for fundamental frequency, vocal attractiveness and formant frequencies were not significantly correlated. Collectively, our results suggest that averageness may not necessarily significantly increase attractiveness judgments of voices and are consistent with previous work reporting significant associations between attractiveness and voice pitch.

Perceptions of employability related to severity of hypernasality: a pilot study

The primary aim of this investigation was to evaluate listener auditory-perceptual assessment of employability for individuals with hypernasal speech. Using an online survey platform, listeners with managerial experience evaluated speech samples from individuals with varying hypernasal resonance disorder severity to determine auditory-perceptual judgements regarding intelligence and employability. Speech samples of individuals with hypernasal speech were rated lower on scales of intelligence and employability, and more likely to be selected for jobs with infrequent rates of communication and lower levels of responsibility. Additionally, males with hypernasal speech were perceived as less intelligent, less employable, and more likely to be selected for a job with infrequent communication in comparison to females with hypernasal speech. Results of this preliminary investigation suggest that individuals with hypernasal speech may face employment barriers. The conclusions collected from this initial investigation open the doors for further research addressing linguistic considerations and aspects of employability. This is an important consideration for individuals with either acquired or congenitally related hypernasal resonance disorder.

Latoszek B, Hunter EJ. Clinical Utility and Validation of the Acoustic Voice Quality and Acoustic Breathiness Indexes for Voice Disorder Assessment in English Speakers

BACKGROUND

While several acoustic voice metrics are available for clinical voice assessment, there remains a significant need for reliable and ecologically valid tools. The Acoustic Voice Quality Index version 03.01 (AVQI-3) and Acoustic Breathiness Index (ABI) hold potential due to their comprehensive assessment approach, incorporating diverse voice aspects. However, these tools still need to be validated in English-speaking populations.

METHODS

This study assessed the discriminatory accuracy and validity of AVQI-3 and ABI in 197 participants, including 148 with voice disorders. Voice samples were collected, followed by AVQI-3 and ABI calculations. Additionally, auditory-perceptual assessments were conducted by a panel of speech-language pathologists.

RESULTS

AVQI-3 and ABI effectively identified disordered voice quality, evidenced by high accuracy (AUCs: 0.84, 0.89), sensitivity, and specificity (thresholds: AVQI-3 = 1.17, ABI = 2.35). Strong positive correlations were observed with subjective voice quality assessments (rs = 0.72, rs = 0.77, p < 0.001).

CONCLUSIONS

The study highlights AVQI-3 and ABI as promising instruments for clinically assessing voice disorders in U.S. English speakers, underscoring their utility in clinical practice and voice research.

The impact of a speaker's voice quality on auditory perception and cognition: a behavioral and subjective approach

Introduction

Our voice is key for conveying information and knowledge to others during verbal communication. However, those who heavily depend on their voice, such as teachers and university professors, often develop voice problems, signaled by hoarseness. The aim of this study was to investigate the effect of hoarseness on listeners' memory for auditory-verbal information, listening effort, and listening impression.

Methods

Forty-eight normally hearing adults performed two memory tasks that were auditorily presented in varied voice quality (typical vs. hoarse). The tasks were Heard Text Recall, as part of a dual-task paradigm, and auditory Verbal Serial Recall (aVSR). Participants also completed a listening impression questionnaire for both voice qualities. Behavioral measures of memory for auditory-verbal information and listening effort were performance and response time. Subjective measures of listening effort and other aspects of listening impression were questionnaire rating scores.

Results

Results showed that, except for the aVSR, behavioral outcomes did not vary with the speaker's voice quality. Regarding the aVSR, we found a significant interaction between voice quality and trial, indicating that participants' recall performance dropped in the beginning of the task in the hoarse-voice condition but not in the typical-voice condition, and then increased again toward the end. Results from the listening impression questionnaire showed that listening to the hoarse voice resulted in significantly increased perceived listening effort, greater annoyance and poorer self-reported performance.

Discussion

These findings suggest that hoarseness can, at least subjectively, compromise effective listening. Vocal health may be particularly important in the educational context, where listening and learning are closely linked.

Acoustic correlates of perceived personality from Korean utterances in a formal communicative setting

The aim of the present study was to find acoustic correlates of perceived personality from the speech produced in a formal communicative setting-that of Korean customer service employees in particular. This work extended previous research on voice personality impressions to a different sociocultural and linguistic context in which speakers are expected to speak politely in a formal register. To use naturally produced speech rather than read speech, we devised a new method that successfully elicited spontaneous speech from speakers who were role-playing as customer service employees, while controlling for the words and sentence structures they used. We then examined a wide range of acoustic properties in the utterances, including voice quality and global acoustic and segmental properties using Principal Component Analysis. Subjects of the personality rating task listened to the utterances and rated perceived personality in terms of the Big-Five personality traits. While replicating some previous findings, we discovered several acoustic variables that exclusively accounted for the personality judgments of female speakers; a more modal voice quality increased perceived conscientiousness and neuroticism, and less dispersed formants reflecting a larger body size increased the perceived levels of extraversion and openness. These biases in personality perception likely reflect gender and occupation-related stereotypes that exist in South Korea. Our findings can also serve as a basis for developing and evaluating synthetic speech for Voice Assistant applications in future studies.

Impact of Vocal Fry and Speaker Gender on Listener Perceptions of Speaker Personal Attributes

OBJECTIVES

Many studies have investigated listener perceptions of speakers who use vocal fry, but results remain mixed. This study aimed to investigate how vocal fry and speaker gender impact listener perceptions of a speaker's likeability, intelligence, attractiveness, and salary-attainment, described as "attributes." We hypothesized speakers with vocal fry would be evaluated more negatively on all attributes than speakers without vocal fry, with female speakers rated more negatively than male speakers.

METHODS

Twenty nine listeners rated male and female speakers with and without vocal fry on these attributes using a five-point Likert scale.

STUDY DESIGN

This experiment used a randomized mixed methods design with Vocal Fry and Speaker Gender as independent variables predicting attribute ratings.

RESULTS

Results of a MANOVA revealed a significant main effect for Fry (Λ = 0.607; F(4,29) = 4.691; ηp2 = 0.393; P = 0.005), where speakers with vocal fry were rated significantly more negatively than speakers without vocal fry. Additionally, there was a significant Fry by Speaker Gender interaction where female speakers without vocal fry were rated as significantly more attractive [F(1,36) = 13.964; P= 0.003; ηp2 = 0.304] and intelligent [F(1,36) = 10.740; P = 0.001; ηp2 = 0.251] than female speakers with vocal fry. There was no significant difference between ratings of male speakers in either fry condition.

CONCLUSIONS

Female speakers with vocal fry were rated as less attractive and intelligent than female speakers without vocal fry, but perception of male speakers did not change whether or not vocal fry was present in the acoustic signal.

Do Voice-Based Judgments of Socially Relevant Speaker Traits Differ Across Speech Types?

PURPOSE

The human voice is a powerful and evolved social tool, with hundreds of studies showing that nonverbal vocal parameters robustly influence listeners' perceptions of socially meaningful speaker traits, ranging from perceived gender and age to attractiveness and trustworthiness. However, these studies have utilized a wide variety of voice stimuli to measure listeners' voice-based judgments of these traits. Here, in the largest scale study known to date, we test whether listeners judge the same unseen speakers differently depending on the complexity of the neutral speech stimulus, from single vowel sounds to a full paragraph.

METHOD

In a playback experiment testing 2,618 listeners, we examine whether commonly studied voice-based judgments of attractiveness, trustworthiness, dominance, likability, femininity/masculinity, and health differ if listeners hear isolated vowels, a series of vowels, single words, single sentences (greeting), counting from 1 to 10, or a full paragraph recited aloud (Rainbow Passage), recorded from the same 208 men and women. Data were collected using a custom-designed interface in which vocalizers and traits were randomly assigned to raters.

RESULTS

Linear-mixed models show that the type of voice stimulus does indeed consistently affect listeners' judgments. Overall, ratings of attractiveness, trustworthiness, dominance, likability, health, masculinity among men, and femininity among women increase as speech duration increases. At the same time, speaker-level regression analyses show that interindividual differences in perceived speaker traits are largely preserved across voice stimuli, especially among those of a similar duration.

CONCLUSIONS

Socially relevant perceptions of speakers are not wholly changed but rather moderated by the length of their speech. Indeed, the same vocalizer is perceived in a similar way regardless of which neutral statements they speak, with the caveat that longer utterances explain the most shared variance in listeners' judgments and elicit the highest ratings on all traits, possibly by providing additional nonverbal information to listeners.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21158890.

Evaluating automatic creaky voice detection methods

There is growing interest in research on the non-modal voice quality, creaky voice; however, its identification often relies on time-consuming manual annotation, leading to a recent focus on automatic creak detection methods. Various automatic methods have been proposed, which rely on varying types and combinations of acoustic cues for creak detection. In this paper, we compare the performance of three automatic tools, the AntiMode method, the Creak Detector algorithm, and the Roughness algorithm, against manual annotation of creak using data from 80 Australian English speakers. We explore the possibility that tools used in combination may yield more accurate creak detection than individual tools used alone. Based on method comparisons, we present options for researchers, including an "out-of-the-box" approach, which supports combining automatic tools, and propose additional steps to further improve creak detection. We found restricting analysis to sonorant segments significantly improves automatic creak detection, and tools performed consistently better on female speech than male speech. Findings support previous work showing detection may be optimised by performing a creak probability threshold sweep on a subset of data prior to applying the Creak Detector algorithm on new datasets. Results provide promising solutions for advancing efficient large-scale research on creaky voice.

Modeling Noise-Related Timbre Semantic Categories of Orchestral Instrument Sounds With Audio Features, Pitch Register, and Instrument Family

Audio features such as inharmonicity, noisiness, and spectral roll-off have been identified as correlates of "noisy" sounds. However, such features are likely involved in the experience of multiple semantic timbre categories of varied meaning and valence. This paper examines the relationships of stimulus properties and audio features with the semantic timbre categories raspy/grainy/rough, harsh/noisy, and airy/breathy. Participants (n = 153) rated a random subset of 52 stimuli from a set of 156 approximately 2-s orchestral instrument sounds representing varied instrument families (woodwinds, brass, strings, percussion), registers (octaves 2 through 6, where middle C is in octave 4), and both traditional and extended playing techniques (e.g., flutter-tonguing, bowing at the bridge). Stimuli were rated on the three semantic categories of interest, as well as on perceived playing exertion and emotional valence. Correlational analyses demonstrated a strong negative relationship between positive valence and perceived physical exertion. Exploratory linear mixed models revealed significant effects of extended technique and pitch register on valence, the perception of physical exertion, raspy/grainy/rough, and harsh/noisy. Instrument family was significantly related to ratings of airy/breathy. With an updated version of the Timbre Toolbox (R-2021 A), we used 44 summary audio features, extracted from the stimuli using spectral and harmonic representations, as input for various models built to predict mean semantic ratings for each sound on the three semantic categories, on perceived exertion, and on valence. Random Forest models predicting semantic ratings from audio features outperformed Partial Least-Squares Regression models, consistent with previous results suggesting that non-linear methods are advantageous in timbre semantic predictions using audio features. Relative Variable Importance measures from the models among the three semantic categories demonstrate that although these related semantic categories are associated in part with overlapping features, they can be differentiated through individual patterns of audio feature relationships.

Vocal Fry Patterns While Reading

INTRODUCTION

The use of vocal fry is common in running speech and has potential psychosocial and vocal health consequences. Determining the different patterns of vocal fry is relevant to differentiating phonatory function, understanding cultural and linguistic use of vocal fry, and clinical diagnostics and intervention. The purpose of this project was to study and categorize patterns of vocal fry in running speech.

METHODOLOGY

Analyses were performed on recordings of the Rainbow Passage read out loud by five healthy females 18-21 years old. Praat was used to create audio files with text grids. The audio recordings were examined visually (the audio signal and its spectrogram) and perceptually in order to determine different patterns of vocal fry seen in the audio signal. Criteria for detecting vocal fry were (1) the presence of an acoustic transient (a relatively large and fast dip in acoustic pressure, presumably near glottal closure) with a relatively long cycle period compared to normal phonation periods, or (2) a frequency at or lower than approximately an octave below the nearby normal speaking fundamental frequency.

RESULTS

There were 174 total vocal fry samples obtained from the recordings. Six vocal fry patterns were observed. The patterns were: single pulse fry (FRY1), double pulse fry (FRY2), multiple pulse fry (FRY3), period doubling fry (FRY4), inaudible fry (FRY5), and indeterminate vocal fry (FRY6). Single pulse fry was divided into a single (one) pulse fry cycle (FRY1a), a series of even single pulse fry cycles (FRY1b), and a series of uneven single pulse fry cycles (FRY1c). Double pulse fry was divided into a primary then another primary pulse fry cycle (FRY2a), a secondary then a primary pulse fry cycle (FRY2b), and a primary then a secondary pulse fry cycle (FRY2c). Multiple pulse fry, where a higher frequency was modulated by a lower frequency, was divided into the higher frequency being near the speaking fundamental frequency (FRY3a) and the higher frequency being inconsistent or well below the expected speaking fundamental frequency (FRY3b). The category single pulse fry had the most samples, with 76% of the total occurrences, followed by period doubling 13%, and the rest 11%. Relative to where the fry patterns occurred within syllables, 36% occurred at the onset of the syllable, 26% early in the syllable, 25% later in the syllable, and 13% at the end of the syllable. These tallies did not include the sixth category, indeterminate vocal fry (FRY6), which was not included in the study proper but recognized as indicating complicated patterns that did not fall within the first five categories.

CONCLUSIONS

Vocal fry is a complex, multifaceted phenomenon. The results of this study suggest that there are identifiable patterns of vocal fry. These patterns need to be differentiated especially regarding the glottal adductory nature and phonatory function of each pattern, glottal closure appearing to be the primary physiological causative factor of the salient negative pressure dips (the adduction behavior will be reported in a study in progress). Further research is necessary to determine other potential categories of vocal fry, determine if there are individual idiosyncratic patterns of vocal fry, determine possible differences in vocal fry produced by individuals of different ages and gender expression and other factors, and research the physiologic, acoustic, aerodynamic, and perceptual reality of each pattern.

Hong Kong Women Project a Larger Body When Speaking to Attractive Men

In this pilot study we investigated the vocal strategies of Cantonese women when addressing an attractive vs. unattractive male. We recruited 19 young female native speakers of Hong Kong Cantonese who completed an attractiveness rating task, followed by a speech production task where they were presented a subset of the same faces. By comparing the rating results and corresponding acoustic data of the facial stimuli, we found that when young Cantonese women spoke to an attractive male, they were less breathy, lower in fundamental frequency, and with denser formants, all of which are considered to project a larger body. Participants who were more satisfied with their own height used these vocal strategies more actively. These results are discussed in terms of the body size projection principle.

Phonation Types Matter in Sound Symbolism

Sound symbolism is a non-arbitrary correspondence between sound and meaning. The majority of studies on sound symbolism have focused on consonants and vowels, and the sound-symbolic properties of suprasegmentals, particularly phonation types, have been largely neglected. This study examines the size and shape symbolism of four phonation types: modal and creaky voices, falsetto, and whisper. Japanese speakers heard 12 novel words (e.g., /íbi/, /ápa/) pronounced with the four types of phonation and rated the size and roundedness/pointedness each of the 48 stimuli seemed to represent on seven-point scales. The results showed that phonation types as well as consonantal and vocalic features influenced the ratings. Creaky voice was associated with larger and more pointed images than modal voice, which was in turn associated with larger and more pointed images than whisper. Falsetto was also associated with roundedness but not with smallness. These results shed new light on the acoustic approaches to sound symbolism and suggest the significance of phonation types and other suprasegmental features in the phenomenon.

Language as a Social Cue

Social groups are a pervasive feature of human life. One factor that is often understudied in the literature on person perception and social categorization is language. Yet, someone's language (and accent) provides a tremendous amount of social information to a listener. Disciplines across the social and behavioral sciences-ranging from linguistics to anthropology to economics-have exposed the social significance of language. Less social psychological research has historically focused on language as a vehicle for social grouping. Yet, new approaches in psychology are reversing this trend. This article first reviews evidence, primarily from psycholinguistics, documenting how speech provides social information. Next it turns to developmental psychology, showing how young humans begin to see others' language as conveying social group information. It then explores how the tendency to see language as a social cue has vast implications for people's psychological processes (e.g., psychological essentialism and trust) and also for society, including education and the law.

The versatility of creaky phonation: Segmental, prosodic, and sociolinguistic uses in the world's languages

Creaky phonation (also known as creaky voice, vocal fry, laryngealization, or glottalization) is a voice quality that refers to shortened and thickened vocal folds that vibrate at a low and quasi-regular fundamental frequency with a long period of damping. Cross-linguistically, creaky phonation can span either short or long domains. When implemented on individual vowels or consonants (as in Zapotec or Montana Salish), it can signal phonemic contrast with other voice qualities, or it can be an additional acoustic cue to enhance other contrasts, such as tone (as in Mandarin or Cantonese). Another segmental use of creaky phonation in many languages is as a variant of glottal stop. Creaky phonation can also be implemented as a prosodic element that signals the end of a phrase (as in English or Mandarin), or indicates relinquishing a conversational turn (as in Finnish). It can also express meaning in a social interaction, such as irritation (in Vietnamese). Lastly, creaky phonation can be deployed as a sociolinguistic marker to establish identities, convey affect, or distinguish one speech group from another within the same language. In some social circumstances, such as the perception that young women use creaky phonation at greater rates than men do, it can be evaluated negatively by listeners. As creaky phonation can be combined with linguistic elements at various levels and is easily perceptible, it has taken on a remarkable number of roles in our linguistic repertoires. This article is categorized under: Linguistics > Language in Mind and Brain.

Let's talk about pain and opioids: Low pitch and creak in medical consultations

In recent years, the opioid crisis in the United States has sparked significant discussion on doctor-patient interactions concerning chronic pain treatments, but little to no attention has been given to investigating the vocal aspects of patient talk. This exploratory sociolinguistic study intends to fill this knowledge gap by employing prosodic discourse analysis to examine context-specific linguistic features used by the interlocutors of two distinct medical interactions. We found that patients employed both low pitch and creak as linguistic resources when describing chronic pain, narrating symptoms, and requesting opioids. The situational use of both features informs us about the linguistic ways in which patients frame fraught issues like chronic pain in light of the current opioid crisis. This study expands the breadth of phonetic analysis within the domain of discourse analysis, serving to illuminate discussions surrounding the illocutionary role of the lower vocal tract in expressing emotions.

The quantitative prevalence of creaky voice (vocal fry) in varieties of English: A systematic review of the literature

Background/aim

It is widely believed that ‘creaky voice’ (‘creak’, ‘vocal fry’, ‘glottal fry’) is increasingly prevalent among some English speakers, particularly among young American women. Motivated by the widespread and cross-disciplinary interest in the phenomenon, this paper offers a systematic review of peer-reviewed research (up to January 2019) on the prevalence of creaky voice in varieties of English. The review aimed to understand whose and what speech has been studied, how creaky voice prevalence has been measured, and what the findings collectively reveal.

Method

Literature was located by searching four electronic databases (ProQuest, PubMed, SCOPUS, Web of Science) and the proceedings of two recurrent conferences (‘ICPhS’ and ‘SST’). Studies were included if they reported the prevalence of creaky voice in naturalistic samples of English spoken by vocally-healthy speakers. Reference lists of included studies were cross-checked.

Results

Only ten studies meeting inclusion criteria were identified. All studies sampled a small number of speakers and/or short durations of speech. Nine were recent studies of American-English speakers, and many of these sampled young, female, college students. Across the ten studies, creaky voice was detected using three types of methods, and prevalence was calculated using five different formulae. The findings show that prevalence varies across groups, individuals, and contexts. However, the precise nature of this variability remains unclear due to the scarcity and methodological heterogeneity of the research.

Conclusions

This paper illustrated the application of systematic literature review methods in sociophonetic research—a field in which such methods are not common. The review found that creaky voice prevalence in English is not well understood, and that widespread claims of its recent increase among young American women have not been empirically confirmed. A number of specific limitations in the existing research are highlighted, which may serve as a guide for future research design.

Continuous Vocal Fry Simulated in Laboratory Subjects: A Preliminary Report on Voice Production and Listener Ratings

PURPOSE

Vocal fry is prevalent in everyday speech. However, whether the use of vocal fry is detrimental to voice production is unclear. This preliminary study assessed the effects of using continuous vocal fry on voice production measures and listener ratings.

METHOD

Ten healthy individuals (equal male and female, mean age = 22.4 years) completed 2 counterbalanced sessions. In each session, participants read in continuous vocal fry or habitual voice quality for 30 min at a comfortable intensity. Continuous vocal fry was simulated. Phonation threshold pressure (PTP10 and PTP20), cepstral peak prominence, and vocal effort ratings were obtained before and after the production of each voice quality. Next, 10 inexperienced listeners (equal male and female, mean age = 24.1 years) used visual analog scales to rate paired samples of continuous vocal fry and habitual voice quality for naturalness, employability, and amount of listener concentration.

RESULTS

PTP10 and vocal effort ratings increased after 30 min of continuous vocal fry. Inexperienced listeners rated continuous vocal fry more negatively than the habitual voice quality.

CONCLUSIONS

Thirty minutes of simulated, continuous vocal fry worsened some voice measures when compared with a habitual voice quality. Samples of continuous vocal fry were rated as significantly less employable, less natural, and requiring greater listener concentration as compared with samples of habitual voice quality. Future studies should include habitual users of vocal fry to investigate speech stimulability and adaptation with cueing to further understand pathogenesis of vocal fry.

The Effects of Pitch, Gender, and Prosodic Context on the Identification of Creaky Voice

BACKGROUND/AIMS

Creaky voice in American English plays both a prosodic role, as a phrase-final marker, and a sociolinguistic one, but it is unclear how accurately naïve listeners can identify creak, and what factors facilitate or hinder ist identification.

METHODS

In this study, American listeners are presented with 2 experiments containing stimuli from both high- and low-pitched male and female speakers. Other manipulations include whether the auditory stimulus is a full sentence or a sentence fragment, and whether it is completely modally voiced, completely creaky, or partially creaky (final 40-50% of the utterance).

RESULTS

Accuracy is lowest on partial creak, suggesting that creaky voice is least salient when it serves as an utterance-final marker. There are no strong gender effects aside from a weak tendency to identify creak more often in females than males in the whole creak condition in one experiment. In contrast, when no creak is present, listeners false alarm on the low-pitched males.

CONCLUSION

Rates of identifying creak in male and female speakers are similar, suggesting that listeners have a comparable ability to hear creaky voice in all speakers.

Vocal Fry and Vowel Height in Simulated Room Acoustics

PURPOSE

The purpose of this study was to investigate the influence of room acoustics in the relationship between vowel height and vocal fry.

METHODS

This was a cross-sectional study. Participants (college students, n = 40) read the first six sentences of "The Rainbow Passage" under nine simulated room acoustic conditions. Using two words with low vowels (act, pot) and two words with high vowels (shape, strikes) preceding a voiceless stop, the presence/absence of vocal fry was assessed using an automatic detection script. Generalized estimation equations were used to investigate the relationship between percentage of vocal fry, vowel height, and room acoustics.

RESULTS

The percentage of vocal fry was significantly higher for the low-height vowels compared with the high-height vowels (β = 1.21; standard er ror = 0.35), and for pink background noise present (β = 0.89; standard error = 0.35) compared with the condition without artificial noise added.

CONCLUSION

The results of this study indicate that young college students are more likely to produce fry phonation when producing low-height vowels under pink background noise condition compared with no noise conditions and high-height vowels. This result is of special interest for voice clinicians when designing therapy plans and vocal assessment protocols with fry-like components.

Perception of Non-Vibrato Sung Tones: A Pilot Study

OBJECTIVES/HYPOTHESIS

Singers are often asked to sing with a non-vibrato production. The term non-vibrato is problematic in that it is not possible for a human to sing a tone without fundamental frequency variation. Whether a singer achieves a quality of tone that is perceived as non-vibrato is an aurally subjective matter. The specific aim of this study was to determine when a tone is perceived as non-vibrato by a population of singers, voice teachers, choir directors, and speech pathologists. Using voice samples that exhibit a variety of vibrato rates and extents, the investigators sought to determine (1) if there is a threshold for the perception of non-vibrato tone with regard to vibrato extent; (2) if vibrato rate, given similar vibrato extent, does affect the perceptual threshold of non-vibrato tone; and (3) if there are differences in the perceptual threshold of non-vibrato tone across the different professions of the research subjects.

STUDY DESIGN

Survey.

METHODS

Participants responded to an online survey featuring 40 randomized samples of soprano voices singing [ɑ] with a variety of vibrato rates and extents. Some samples were repeated to test subject response reliability.

RESULTS AND CONCLUSIONS

Results indicate that a perceptual threshold exists with regard to vibrato extent. However, vibrato rate significantly affected where this extent threshold occurred for the participants. Vibrato extent and rate work together to affect perception of non-vibrato tone. Significant differences were not found across the different groups.