Perceptual (but not acoustic) features predict singing voice preferences.

Why do we prefer some singers to others? We investigated how much singing voice preferences can be traced back to objective features of the stimuli. To do so, we asked participants to rate short excerpts of singing performances in terms of how much they liked them as well as in terms of 10 perceptual attributes (e.g.: pitch accuracy, tempo, breathiness). We modeled liking ratings based on these perceptual ratings, as well as based on acoustic features and low-level features derived from Music Information Retrieval (MIR). Mean liking ratings for each stimulus were highly correlated between Experiments 1 (online, US-based participants) and 2 (in the lab, German participants), suggesting a role for attributes of the stimuli in grounding average preferences. We show that acoustic and MIR features barely explain any variance in liking ratings; in contrast, perceptual features of the voices achieved around 43% of prediction. Inter-rater agreement in liking and perceptual ratings was low, indicating substantial (and unsurprising) individual differences in participants' preferences and perception of the stimuli. Our results indicate that singing voice preferences are not grounded in acoustic attributes of the voices per se, but in how these features are perceptually interpreted by listeners.

The Sound of Emotional Prosody: Nearly 3 Decades of Research and Future Directions.

Emotional voices attract considerable attention. A search on any browser using "emotional prosody" as a key phrase leads to more than a million entries. Such interest is evident in the scientific literature as well; readers are reminded in the introductory paragraphs of countless articles of the great importance of prosody and that listeners easily infer the emotional state of speakers through acoustic information. However, despite decades of research on this topic and important achievements, the mapping between acoustics and emotional states is still unclear. In this article, we chart the rich literature on emotional prosody for both newcomers to the field and researchers seeking updates. We also summarize problems revealed by a sample of the literature of the last decades and propose concrete research directions for addressing them, ultimately to satisfy the need for more mechanistic knowledge of emotional prosody.

Classical singers are also proficient in non-classical singing.

Classical singers train intensively for many years to achieve a high level of vocal control and specific sound characteristics. However, the actual span of singers' activities often includes venues other than opera halls and requires performing in styles outside their strict training (e.g., singing pop songs at weddings). We examine classical singers' ability to adjust their vocal productions to other styles, in relation with their formal training. Twenty-two highly trained female classical singers (aged from 22 to 45 years old; vocal training ranging from 4.5 to 27 years) performed six different melody excerpts a cappella in contrasting ways: as an opera aria, as a pop song and as a lullaby. All melodies were sung both with lyrics and with a /lu/ sound. All productions were acoustically analyzed in terms of seven common acoustic descriptors of voice/singing performances and perceptually evaluated by a total of 50 lay listeners (aged from 21 to 73 years old) who were asked to identify the intended singing style in a forced-choice lab experiment. Acoustic analyses of the 792 performances suggest distinct acoustic profiles, implying that singers were able to produce contrasting sounding performances. Furthermore, the high overall style recognition rate (78.5% Correct Responses, hence CR) confirmed singers' proficiency in performing in operatic style (86% CR) and their versatility when it comes to lullaby (80% CR) and pop performances (69% CR), albeit with occasional confusion between the latter two. Interestingly, different levels of competence among singers appeared, with versatility (as estimated based on correct recognition in pop/lullaby styles) ranging from 62 to 83% depending on the singer. Importantly, this variability was not linked to formal training per se. Our results indicate that classical singers are versatile, and prompt the need for further investigations to clarify the role of singers' broader professional and personal experiences in the development of this valuable ability.

Ironic twists of sentence meaning can be signaled by forward move of prosodic stress.

Prosodic stresses are known to affect the meaning of utterances, but exactly how they do this is not known in many cases. We focus on the mechanisms underlying the meaning effects of ironic prosody (e.g., teasing or blaming through an ironic twist), which is frequently used in both personal and mass-media communication. To investigate ironic twists, we created 30 sentences that can be interpreted both ironically and nonironically, depending on the context. In Experiment 1, 14 of these sentences were identified as being most reliably understood in the two conditions. In Experiment 2, we recorded the 14 sentences spoken in both a literal and an ironic condition by 14 speakers, and the resulting 392 recorded sentences were acoustically analyzed. In Experiment 3, 20 listeners marked the acoustically prominent words, thus identifying perceived prosodic stresses. In Experiment 4, 53 participants rated how ironic they perceived the 392 recorded sentences to be. The combined analysis of irony ratings, acoustic features, and various prosodic stress characteristics revealed that ironic meaning is primarily signaled by a stress shift from the end of a sentence to an earlier position. This change in position might function as a "warning" cue for listeners to consider potential alternative meanings of the sentence. Thus, beyond giving individual words a stronger contrastive or emphatic role, the distribution of prosodic stresses can also prime opposite meanings for identical sentences, supporting the view that the dynamic aspect of prosody conveys important cues in human communication. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Modelling individual and cross-cultural variation in the mapping of emotions to speech prosody.

The existence of a mapping between emotions and speech prosody is commonly assumed. We propose a Bayesian modelling framework to analyse this mapping. Our models are fitted to a large collection of intended emotional prosody, yielding more than 3,000 minutes of recordings. Our descriptive study reveals that the mapping within corpora is relatively constant, whereas the mapping varies across corpora. To account for this heterogeneity, we fit a series of increasingly complex models. Model comparison reveals that models taking into account mapping differences across countries, languages, sexes and individuals outperform models that only assume a global mapping. Further analysis shows that differences across individuals, cultures and sexes contribute more to the model prediction than a shared global mapping. Our models, which can be explored in an online interactive visualization, offer a description of the mapping between acoustic features and emotions in prosody.

Are You Your Own Best Judge? On the Self-Evaluation of Singing.

OBJECTIVE: Singers are the first judges of their own performances. Although performers usually share a precise definition of pitch accuracy, do they correctly estimate their own ability to sing in tune? This study examines the accuracy of professional singers' self-evaluations and investigates the profiles of performers/judges. METHODS: Eighteen highly trained soprano singers were invited to evaluate the pitch accuracy of peers' performances, selected from an existing corpus, and their own previously recorded performances in a pairwise comparison paradigm. The statistical model derived from the participants' evaluation of their peers allowed us to estimate the pitch accuracy of participants' own performances and served as a reference to quantify participants' evaluation and self-evaluation abilities. RESULTS: The results show that participants were surprisingly inaccurate when evaluating themselves. Specifically, most participants overestimated the accuracy of their own performances. Also, we observed a relationship between singing proficiency and self-evaluation ability, as well as the presence of different profiles. CONCLUSION: In addition to emphasizing that singers are not necessarily their own best judges, this study suggests potential role(s) for self-evaluation (in)accuracy in the development of exceptional skills.

The variably intense vocalizations of affect and emotion (VIVAE) corpus prompts new perspective on nonspeech perception.

The human voice is a potent source of information to signal emotion. Nonspeech vocalizations (e.g., laughter, crying, moans, or screams), in particular, can elicit compelling affective experiences. Consensus exists that the emotional intensity of such expressions matters; however how intensity affects such signals, and their perception remains controversial and poorly understood. One reason is the lack of appropriate data sets. We have developed a comprehensive stimulus set of nonverbal vocalizations, the first corpus to represent emotion intensity from one extreme to the other, in order to resolve the empirically underdetermined basis of emotion intensity. The full set, comprising 1085 stimuli, features eleven speakers expressing 3 positive (achievement/triumph, sexual pleasure, surprise) and 3 negative (anger, fear, physical pain) affective states, each varying from low to peak emotion intensity. The smaller core set of 480 files represents a fully crossed subsample (6 emotions × 4 intensities × 10 speakers × 2 items) selected based on judged authenticity. Perceptual validation and acoustic characterization of the stimuli are provided; the expressed emotional intensity, like expressed emotion, is reflected in listener evaluation and signal properties of nonverbal vocalizations. These carefully curated new materials can help disambiguate foundational questions on the communication of affect and emotion in the psychological and neural sciences and strengthen our theoretical understanding of this domain of emotional experience. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Perception of Nigerian Dùndún Talking Drum Performances as Speech-Like vs. Music-Like: The Role of Familiarity and Acoustic Cues.

It seems trivial to identify sound sequences as music or speech, particularly when the sequences come from different sound sources, such as an orchestra and a human voice. Can we also easily distinguish these categories when the sequence comes from the same sound source? On the basis of which acoustic features? We investigated these questions by examining listeners' classification of sound sequences performed by an instrument intertwining both speech and music: the dùndún talking drum. The dùndún is commonly used in south-west Nigeria as a musical instrument but is also perfectly fit for linguistic usage in what has been described as speech surrogates in Africa. One hundred seven participants from diverse geographical locations (15 different mother tongues represented) took part in an online experiment. Fifty-one participants reported being familiar with the dùndún talking drum, 55% of those being speakers of Yorùbá. During the experiment, participants listened to 30 dùndún samples of about 7s long, performed either as music or Yorùbá speech surrogate (n = 15 each) by a professional musician, and were asked to classify each sample as music or speech-like. The classification task revealed the ability of the listeners to identify the samples as intended by the performer, particularly when they were familiar with the dùndún, though even unfamiliar participants performed above chance. A logistic regression predicting participants' classification of the samples from several acoustic features confirmed the perceptual relevance of intensity, pitch, timbre, and timing measures and their interaction with listener familiarity. In all, this study provides empirical evidence supporting the discriminating role of acoustic features and the modulatory role of familiarity in teasing apart speech and music.

Listening to birdsong reveals basic features of rate perception and aesthetic judgements.

The timing of acoustic events is central to human speech and music. Tempo tends to be slower in aesthetic contexts: rates in poetic speech and music are slower than non-poetic, running speech. We tested whether a general aesthetic preference for slower rates can account for this, using birdsong as a stimulus: it structurally resembles human sequences but is unbiased by their production or processing constraints. When listeners selected the birdsong playback tempo that was most pleasing, they showed no bias towards any range of note rates. However, upon hearing a novel stimulus, listeners rapidly formed a robust, implicit memory of its temporal properties, and developed a stimulus-specific preference for the memorized tempo. Interestingly, tempo perception in birdsong stimuli was strongly determined by individual, internal preferences for rates of 1-2 Hz. This suggests that processing complex sound sequences relies on a default time window, while aesthetic appreciation appears flexible, experience-based and not determined by absolute event rates.

The mistuning perception test: A new measurement instrument.

An important aspect of the perceived quality of vocal music is the degree to which the vocalist sings in tune. Although most listeners seem sensitive to vocal mistuning, little is known about the development of this perceptual ability or how it differs between listeners. Motivated by a lack of suitable preexisting measures, we introduce in this article an adaptive and ecologically valid test of mistuning perception ability. The stimulus material consisted of short excerpts (6 to 12 s in length) from pop music performances (obtained from MedleyDB; Bittner et al., 2014) for which the vocal track was pitch-shifted relative to the instrumental tracks. In a first experiment, 333 listeners were tested on a two-alternative forced choice task that tested discrimination between a pitch-shifted and an unaltered version of the same audio clip. Explanatory item response modeling was then used to calibrate an adaptive version of the test. A subsequent validation experiment applied this adaptive test to 66 participants with a broad range of musical expertise, producing evidence of the test's reliability, convergent validity, and divergent validity. The test is ready to be deployed as an experimental tool and should make an important contribution to our understanding of the human ability to judge mistuning.

The Effect of Smoking on the Fundamental Frequency of the Speaking Voice.

OBJECTIVE: Little is known about the impact of smoking on voice acoustics. Some studies have found that tobacco affects the fundamental frequency of the voice, whereas others have not. This study aimed to overcome the major methodological limitations observed in previous studies by strictly controlling several variables that could clarify the effect of smoking on the speaking voice. METHODS: Lebanese men were chosen for this study. Thirty nonsmokers, 30 cigarette smokers, and 30 water-pipe smokers were matched on the basis of age, height, and weight. The 90 participants were asked to complete the Voice Handicap Index, sustain the vowel /a/, read 10 sentences in French and Arabic, and speak spontaneously in both languages. The mean fundamental frequency (F0), speaking fundamental frequency (SFF), jitter, and standard deviation of F0 were measured using Praat and Vocalab4 and were compared between the groups. RESULTS: The Voice Handicap Index scores differed significantly between nonsmokers and cigarette smokers and between nonsmokers and water-pipe smokers. Results also show that cigarette smokers' F0 and SFF were significantly lower than nonsmokers' results. No significant differences were found between water-pipe smokers and nonsmokers. The jitter and the standard deviation of F0 did not differ significantly between the two groups. CONCLUSIONS: Our findings clearly demonstrate the effect of smoking on the voice: smokers reported more voice complaints, and cigarette smokers presented lower F0 and SFF in French and in Arabic when age, height, and weight were controlled. Further investigations using similar strict controls over individual variables and additional measures are encouraged to better understand the effect of water-pipe smoking on the voice.

Pitch perception in music: Do scoops matter?

Studies of musical pitch perception typically treat pitches as if they are stable within a tone. Although pitches are represented this way in notation, performed tones are rarely stable, particularly in singing, which is arguably the most common form of melody production. This paper examines how brief dynamic changes at the beginnings and endings of sung pitches, a.k.a. "scoops," influence intonation perception. Across three experiments, 110 participants evaluated the intonation of four-tone melodies in which the third tone's tuning could vary within the central steady-state (the asymptote), or by virtue of scoops at the beginning and/or end of the tone. As expected, listeners were sensitive to mistuning. Importantly, our results also point to unique contributions of scoops. As in the language domain, dynamic changes in a small time window are perceptually significant in music. More specifically, this study revealed the coexistence of two distinct mechanisms: sensitivity to the average pitch across the duration of the tone (assimilating the scoop), and processing the relationship of the scoop to the surrounding context. In addition to clarifying intonation perception in music, the identification of these mechanisms paves the way to cross-domain comparisons and, more generally, to the better understanding of auditory sequences processing. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Vocal Features of Song and Speech: Insights from Schoenberg's Pierrot Lunaire.

Similarities and differences between speech and song are often examined. However, the perceptual definition of these two types of vocalization is challenging. Indeed, the prototypical characteristics of speech or song support top-down processes, which influence listeners' perception of acoustic information. In order to examine vocal features associated with speaking and singing, we propose an innovative approach designed to facilitate bottom-up mechanisms in perceiving vocalizations by using material situated between speech and song: Speechsong. 25 participants were asked to evaluate 20 performances of a speechsong composition by Arnold Schoenberg, "Pierrot lunaire" op. 21 from 1912, evaluating 20 features of vocal-articulatory expression. Raters provided reliable judgments concerning the vocal features used by the performers and did not show strong appeal or specific expectations in reference to Schoenberg's piece. By examining the relationship between the vocal features and the impression of song or speech, the results confirm the importance of pitch (height, contour, range), but also point to the relevance of register, timbre, tension and faucal distance. Besides highlighting vocal features associated with speech and song, this study supports the relevance of the present approach of focusing on a theoretical middle category in order to better understand vocal expression in song and speech.

Layman versus Professional Musician: Who Makes the Better Judge?

The increasing number of casting shows and talent contests in the media over the past years suggests a public interest in rating the quality of vocal performances. In many of these formats, laymen alongside music experts act as judges. Whereas experts' judgments are considered objective and reliable when it comes to evaluating singing voice, little is known about laymen's ability to evaluate peers. On the one hand, layman listeners-who by definition did not have any formal training or regular musical practice-are known to have internalized the musical rules on which singing accuracy is based. On the other hand, layman listeners' judgment of their own vocal skills is highly inaccurate. Also, when compared with that of music experts, their level of competence in pitch perception has proven limited. The present study investigates laypersons' ability to objectively evaluate melodies performed by untrained singers. For this purpose, laymen listeners were asked to judge sung melodies. The results were compared with those of music experts who had performed the same task in a previous study. Interestingly, the findings show a high objectivity and reliability in layman listeners. Whereas both the laymen's and experts' definition of pitch accuracy overlap, differences regarding the musical criteria employed in the rating task were evident. The findings suggest that the effect of expertise is circumscribed and limited and supports the view that laypersons make trustworthy judges when evaluating the pitch accuracy of untrained singers.

On drawing a line through the spectrogram: how do we understand deficits of vocal pitch imitation?

In recent years there has been a remarkable increase in research focusing on deficits of pitch production in singing. A critical concern has been the identification of "poor pitch singers," which we refer to more generally as individuals having a "vocal pitch imitation deficit." The present paper includes a critical assessment of the assumption that vocal pitch imitation abilities can be treated as a dichotomy. Though this practice may be useful for data analysis and may be necessary within educational practice, we argue that this approach is complicated by a series of problems. Moreover, we argue that a more informative (and less problematic) approach comes from analyzing vocal pitch imitation abilities on a continuum, referred to as effect magnitude regression, and offer examples concerning how researchers may analyze data using this approach. We also argue that the understanding of this deficit may be better served by focusing on the effects of experimental manipulations on different individuals, rather than attempt to treat values of individual measures, and isolated tasks, as absolute measures of ability.

Singing ability is rooted in vocal-motor control of pitch.

The inability to vocally match a pitch can be caused by poor pitch perception or by poor vocal-motor control. Although previous studies have tried to examine the relationship between pitch perception and vocal production, they have failed to control for the timbre of the target to be matched. In the present study, we compare pitch-matching accuracy with an unfamiliar instrument (the slider) and with the voice, designed such that the slider plays back recordings of the participant's own voice. We also measured pitch accuracy in singing a familiar melody ("Happy Birthday") to assess the relationship between single-pitch-matching tasks and melodic singing. Our results showed that participants (all nonmusicians) were significantly better at matching recordings of their own voices with the slider than with their voice, indicating that vocal-motor control is an important limiting factor on singing ability. We also found significant correlations between the ability to sing a melody in tune and vocal pitch matching, but not pitch matching on the slider. Better melodic singers also tended to have higher quality voices (as measured by acoustic variables). These results provide important evidence about the role of vocal-motor control in poor singing ability and demonstrate that single-pitch-matching tasks can be useful in measuring general singing abilities.

Effects of melody and technique on acoustical and musical features of western operatic singing voices.

OBJECTIVE: The operatic singing technique is frequently used in classical music. Several acoustical parameters of this specific technique have been studied but how these parameters combine remains unclear. This study aims to further characterize the Western operatic singing technique by observing the effects of melody and technique on acoustical and musical parameters of the singing voice. METHODS: Fifty professional singers performed two contrasting melodies (popular song and romantic melody) with two vocal techniques (with and without operatic singing technique). The common quality parameters (energy distribution, vibrato rate, and extent), perturbation parameters (standard deviation of the fundamental frequency, signal-to-noise ratio, jitter, and shimmer), and musical features (fundamental frequency of the starting note, average tempo, and sound pressure level) of the 200 sung performances were analyzed. RESULTS: The results regarding the effect of melody and technique on the acoustical and musical parameters show that the choice of melody had a limited impact on the parameters observed, whereas a particular vocal profile appeared depending on the vocal technique used. CONCLUSIONS: This study confirms that vocal technique affects most of the parameters examined. In addition, the observation of quality, perturbation, and musical parameters contributes to a better understanding of the Western operatic singing technique.

The effects of stress on singing voice accuracy.

OBJECTIVE: The quality of a music performance can be lessened or enhanced if the performer experiences stressful conditions. In addition, the quality of a sung performance requires control of the fundamental frequency of the voice, which is particularly sensitive to stress. The present study aimed to clarify the effects of stress on singing voice accuracy. METHODS: Thirty-one music students were recorded in a stressful condition (ie, a music examination) and a nonstressful condition. Two groups were defined according to the challenge level of the music examination (first and second music levels). Measurements were made by self-reported state anxiety (CSAI-2R questionnaire) and by observing heart rate activity (electrocardiogram) during each performance. In addition, the vocal accuracy of the sung performances was objectively analyzed. RESULTS: As expected, state anxiety and heart rate were significantly higher on the day of the music examination than in the nonstressful condition for all the music students. However, the effect of stress was positive for the first-year students but negative for the second-year students, for whom the music examination was particularly challenging. In addition, highly significant correlations were found between the intensity of cognitive symptoms and the vocal accuracy criteria. DISCUSSION: This study highlights the contrasting effects of stress on singing voice accuracy but also the need to consider the challenge level and perception of the symptoms in experimental and pedagogical settings.

Criteria and tools for objectively analysing the vocal accuracy of a popular song.

This study aims to validate our method for measuring accuracy in a melodic context. We analysed the popular song 'Happy Birthday' sung by 63 occasional and 14 professional singers thanks to AudioSculpt and OpenMusic (IRCAM, Paris, France). In terms of evaluation of the pitch interval deviation, we replicated the profile of occasional singers described in the literature (the slower the performance, the more accurate it is). Our results also confirm that the professional singers sing more accurately than occasional singers but not when a Western operatic singing technique is involved. These results support the relevance of our method for analysing vocal accuracy of occasional and professional singers and led us to discuss adaptations to be implemented for analysing the accuracy of operatic voices.

The effect of melody and technique on the singing voice accuracy of trained singers.

A previous study highlighted the effect of vocal technique on the singing voice accuracy of trained singers. The intervals' precision between the notes of the tune was altered when the singers used Western operatic singing technique. In order better to understand these results, we have recorded two different melodies sung with two different vocal techniques. A large panel of trained singers (n = 50) participated in the study. The analytical method described in the reference paper has been applied. The results confirm the effect of vocal technique on the vocal accuracy of trained singers. In addition, these results provide an answer about the melodic effect and guide future work on the perception process of operatic voices.