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.

The effects of face masks on speech-in-speech recognition for children and adults.

OBJECTIVES: This study explored the effects of different face masks on school-age children's and young adults' word recognition. DESIGN: Speech recognition thresholds were measured adaptively in a two-talker speech masker using a closed-set picture pointing task. Target words were recorded by a female talker in five conditions: no mask, transparent mask, face shield, N95 mask and surgical mask. STUDY SAMPLES: Thirty children (8-12 years) and 25 adults (18-25 years) with normal hearing. RESULTS: Both children's and adults' word recognition was most negatively impacted by the face shield. Children's recognition was also impaired by the transparent mask. No negative effects were observed for the N95 or surgical mask for either age group. CONCLUSION: School-age children, like young adults, are negatively affected by face masks when recognising speech in a two-talker speech masker, but the effects depend on the type of face mask being worn. Acoustic analyses suggest that the reflective materials used for masks impact speech signal quality and impair word recognition.

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

Previous literature suggests that musical performers may be influenced to some extent by the acoustic environment in which they sing or play. This study investigates the influence of room acoustics on singers' voice production, by analyzing consecutive sung performances of classically trained students in five different performance spaces. The analyzed voice parameters were vibrato rate, extent, and pitch inaccuracy. Nine classically trained student-singers performed the same aria unaccompanied on a variable starting pitch that was consistent between spaces. Variance in vibrato rate and pitch inaccuracy was primarily explained by individual differences between singers. Conversely, the variance attributable to the rooms for the parameter of vibrato extent was larger compared to the variance attributable to the performers. Vibrato extent tended to increase with room clarity (C80) and was inversely associated with early decay time (EDT). Additionally, pitch inaccuracy showed a significant negative association with room support (STv). Singers seem to adjust their vocal production when performing in different acoustic environments. Likewise, the degree to which a singer can hear themself on stage may influence pitch accuracy.

Intelligibility of dysphonic speech in auralized classrooms.

Voice disorders can reduce the speech intelligibility of affected speakers. This study evaluated the effect of noise, voice disorders, and room acoustics on vowel intelligibility, listening easiness, and the listener's reaction time. Three adult females with dysphonia and three adult females with normal voice quality recorded a series of nine vowels of American English in /h/-V-/d/ format (e.g., "had"). The recordings were convolved with two oral-binaural impulse responses acquired from measurements in two classrooms with 0.4 and 3.1 s of reverberation time, respectively. The stimuli were presented in a forced-choice format to 29 college students. The intelligibility and the listening easiness were significantly higher in quiet than in noisy conditions, when the speakers had normal voice quality compared to a dysphonic voice, and in low reverberated environments compared to high reverberated environments. The response time of the listener was significantly longer for speech presented in noisy conditions compared to quiet conditions and when the voice was dysphonic compared with healthy voice quality.

Effect of masks on speech intelligibility in auralized classrooms.

This study explored the effects of wearing face masks on classroom communication. The effects of three different types of face masks (fabric, surgical, and N95 masks) on speech intelligibility (SI) presented to college students in auralized classrooms were evaluated. To simulate realistic classroom conditions, speech stimuli were presented in the presence of speech-shaped noise with a signal-to-noise ratio of +3 dB under two different reverberation times (0.4 s and 3.1 s). The use of fabric masks yielded a significantly greater reduction in SI compared to the other masks. Therefore, surgical masks or N95 masks are recommended in teaching environments.

Lombard effect, ambient noise, and willingness to spend time and money in a restaurant.

The objective of this study is to determine the minimum level of noise in a restaurant that starts the Lombard effect, and how it relates to the perceived communication disturbance and the willingness to spend time and money for a meal. Twenty-eight participants were instructed to read a passage in the presence of restaurant noise from 35 to 85 dB(A). As the noise level increased, participants began to be disturbed by the noise at 52 dB(A) and began to raise their voice at 57 dB(A). The willingness to spend time and money decreased starting at 52 dB(A).

Accuracy of the quantities measured by four vocal dosimeters and its uncertainty.

Although vocal dosimeters are often used for long-term voice monitoring, the uncertainty of the quantities measured by these devices is not always stated. In this study, two common vocal dosimetry quantities, mean vocal sound pressure level and mean vocal fundamental frequency, were measured by four vocal dosimeters (VocaLog2, VoxLog, Voice Care, and APM3200). The expanded uncertainty of the mean error in the estimation of these two quantities as measured by the four dosimeters was performed by simultaneously comparing signals acquired through a reference microphone and the devices themselves. Dosimeters, assigned in random order, were worn by the participants (22 vocally healthy adults), along with a head-mounted microphone, which acted as a reference. For each device, participants produced a sustained /a/ vowel four times and then read a text with three different vocal efforts (relaxed, normal, and raised). The measurement uncertainty was obtained by comparing data from the microphone and the dosimeters. The mean vocal sound pressure level was captured the most accurately by the Voice Care and the VoxLog while the APM3200 was the least accurate. The most accurate mean vocal fundamental frequency was estimated by the Voice Care and the APM3200, while the VoxLog was the least accurate.

Speech produced in noise: Relationship between listening difficulty and acoustic and durational parameters.

Conversational speech produced in noise can be characterised by increases in intelligibility relative to such speech produced in quiet. Listening difficulty (LD) is a metric that can be used to evaluate speech transmission performance more sensitively than intelligibility scores in situations in which performance is likely to be high. The objectives of the present study were to evaluate the LD of speech produced in different noise and style conditions, to evaluate the spectral and durational speech modifications associated with these conditions, and to determine whether any of the spectral and durational parameters predicted LD. Nineteen subjects were instructed to speak at normal and loud volumes in the presence of background noise at 40.5 dB(A) and babble noise at 61 dB(A). The speech signals were amplitude-normalised, combined with pink noise to obtain a signal-to-noise ratio of -6 dB, and presented to twenty raters who judged their LD. Vowel duration, fundamental frequency and the proportion of the spectral energy in high vs low frequencies increased with the noise level within both styles. LD was lowest when the speech was produced in the presence of high level noise and at a loud volume, indicating improved intelligibility. Spectrum balance was observed to predict LD.

Teachers' voicing and silence periods during continuous speech in classrooms with different reverberation times.

The relationship between reverberation times and the voicing and silence accumulations of continuous speech was quantified in 22 primary-school teachers. Teachers were divided into a high and a low reverberation time groups based on their classroom reverberation time (higher and lower than 0.90 s). Reverberation times higher than 0.90 s implicate higher voicing accumulations and higher accumulations of the silences typical of turn taking in dialogue. These results suggest that vocal load, which can lead to vocal fatigue, is influenced by classroom reverberation time. Therefore, it may be considered a risk factor for occupational voice users.

The Effect of Classroom Capacity on Vocal Fatigue as Quantified by the Vocal Fatigue Index.

OBJECTIVE: Previous research has concluded that teachers are at a higher-than-normal risk for voice issues that can cause occupational limitations. While some risk factors have been identified, there are still many unknowns. PATIENTS AND METHODS: A survey was distributed electronically with 506 female teacher respondents. The survey included questions to quantify three aspects of vocal fatigue as captured by the Vocal Fatigue Index (VFI): (1) general tiredness of voice (performance), (2) physical discomfort associated with voicing (pain), and (3) improvement of symptoms with rest (recovery). The effect of classroom capacity on US teachers' self-reported experience of vocal fatigue was analyzed. RESULTS: The results indicated that a classroom's capacity significantly affected teachers' reported amounts of vocal fatigue, while a teacher's age also appeared to significantly affect the reported amount of vocal fatigue. A quadratic rather than linear effect was seen, with the largest age effect occurring at around 40-45 years in all three factors of the VFI. CONCLUSION: Further factors which may affect vocal fatigue must be explored in future research. By understanding what increases the risk for vocal fatigue, educators and school administrators can take precautions to mitigate the occupational risk of short- and long-term vocal health issues in school teachers.

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 (ß = 1.21; standard er ror = 0.35), and for pink background noise present (ß = 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.

Evaluation of the starting point of the Lombard Effect.

Speakers increase their vocal effort when their communication is disturbed by noise. This adaptation is termed the Lombard effect. The aim of the present study was to determine whether this effect has a starting point. Hence, the effects of noise at levels between 20 and 65 dB(A) on vocal effort (quantified by sound pressure level) and on both perceived noise disturbance and perceived vocal discomfort were evaluated. Results indicate that there is a Lombard effect change-point at a background noise level (Ln) of 43.3 dB(A). This change-point is anticipated by noise disturbance, and is followed by a high magnitude of vocal discomfort.

Effects of speech style, room acoustics, and vocal fatigue on vocal effort.

Vocal effort is a physiological measure that accounts for changes in voice production as vocal loading increases. It has been quantified in terms of sound pressure level (SPL). This study investigates how vocal effort is affected by speaking style, room acoustics, and short-term vocal fatigue. Twenty subjects were recorded while reading a text at normal and loud volumes in anechoic, semi-reverberant, and reverberant rooms in the presence of classroom babble noise. The acoustics in each environment were modified by creating a strong first reflection in the talker position. After each task, the subjects answered questions addressing their perception of the vocal effort, comfort, control, and clarity of their own voice. Variation in SPL for each subject was measured per task. It was found that SPL and self-reported effort increased in the loud style and decreased when the reflective panels were present and when reverberation time increased. Self-reported comfort and control decreased in the loud style, while self-reported clarity increased when panels were present. The lowest magnitude of vocal fatigue was experienced in the semi-reverberant room. The results indicate that early reflections may be used to reduce vocal effort without modifying reverberation time.

Effects of voice style, noise level, and acoustic feedback on objective and subjective voice evaluations.

Speakers adjust their vocal effort when communicating in different room acoustic and noise conditions and when instructed to speak at different volumes. The present paper reports on the effects of voice style, noise level, and acoustic feedback on vocal effort, evaluated as sound pressure level, and self-reported vocal fatigue, comfort, and control. Speakers increased their level in the presence of babble and when instructed to talk in a loud style, and lowered it when acoustic feedback was increased and when talking in a soft style. Self-reported responses indicated a preference for the normal style without babble noise.

Toward Enhanced Voice-Related Self-Reports: Translation, Cross-Cultural Adaptation, and Validity.

PURPOSE: This article provides a commentary on voice-related self-reports and presents various shortcomings endemic in the development and validation of these measures. Emphasis is placed on issues of construct validity, translation, and cross-cultural adaptation. Finally, a demonstration is provided to elucidate the importance of cross-cultural adaptation. METHODS: An example of a voice-related self-report that lacks cross-cultural adaptation is provided, and a linguistic translation and cross-cultural adaptation process is outlined and demonstrated. A bilingual voice scientist, a bilingual speech-language pathologist (SLP), and two experts in voice-related self-reports completed a multistep linguistic translation and cross-cultural adaptation process and obtained back-translations from five SLPs native to the self-report's source culture. RESULTS: Analyses of the back-translations demonstrated that the mean BiLingual Evaluation Understudy (BLEU) scores of the adapted items were higher overall than the back-translations of the original English items. CONCLUSIONS: Unvalidated translations of voice-related self-reports are commonly used as a baseline to further translate the measure, and this deteriorates cross-cultural health equity. Cross-cultural adaptation is a crucial, but often overlooked process when translating and adapting self-reports. The present article calls for standardized methodologies with an emphasis on the necessity of careful translation methods and cultural adaptation processes.

Impact of cochlear implants use on voice production and quality.

Cochlear implant users experience difficulties controlling their vocalizations compared to normal hearing peers. However, less is known about their voice quality. The primary aim of the present study was to determine if cochlear implant users' voice quality would be categorized as dysphonic by the Acoustic Voice Quality Index (AVQI) and smoothed cepstral peak prominence (CPPS). A secondary aim was to determine if vocal quality is further impacted when using bilateral implants compared to using only one implant. The final aim was to determine how residual hearing impacts voice quality. Twenty-seven cochlear implant users participated in the present study and were recorded while sustaining a vowel and while reading a standardized passage. These recordings were analyzed to calculate the AVQI and CPPS. The results indicate that CI users' voice quality was detrimentally affected by using their CI, raising to the level of a dysphonic voice. Specifically, when using their CI, mean AVQI scores were 4.0 and mean CPPS values were 11.4 dB, which indicates dysphonia. There were no significant differences in voice quality when comparing participants with bilateral implants to those with one implant. Finally, for participants with residual hearing, as hearing thresholds worsened, the likelihood of a dysphonic voice decreased.

Do-It-Yourself Voice Dosimeter Device: A Tutorial and Performance Results.

PURPOSE: Voice dosimeters gather voice production data in the daily lives of individuals with voice disorders. Additionally, voice dosimeters aid in understanding the pathophysiology of voice disorders. Previously, several voice dosimeters were commercially available. However, these devices have been discontinued and are not available to clinicians and researchers alike. In this tutorial, instructions for a low-cost, easy-to-assemble voice dosimeter are provided. This do-it-yourself (DIY) voice dosimeter is further validated based on performance results. METHOD: Ten vocally healthy participants wore the DIY voice dosimeter. They produced a sustained /a/ vowel and read a text with three different vocal efforts. These tasks were recorded by the DIY voice dosimeter and a reference microphone simultaneously. The expanded uncertainty of the mean error in the estimation of four voice acoustic parameters as measured by the DIY dosimeter was performed by comparing the signals acquired through the reference microphone and the dosimeter. RESULTS: For measures of sound pressure level, the DIY voice dosimeter had a mean error of -0.68 dB with an uncertainty of 0.56 dB. For fundamental frequency, the mean error was 1.56 Hz for female participants and 1.11 Hz for male participants, with an uncertainty of 0.62 Hz and 0.34 Hz for female and male participants, respectively. Cepstral peak prominence smoothed and L1 minus L2 had mean errors (uncertainty) of -0.06 dB (0.27 dB) and 2.20 dB (0.72 dB). CONCLUSION: The mean error and uncertainties for the DIY voice dosimeter are comparable to those for the most accurate voice dosimeters that were previously on the market.

Investigating the Impact of Visual Input on Voice Production in Virtual Reality.

OBJECTIVE: This study explored the independent effects of visual input on voice production using virtual reality. Specifically, its effects on acoustic voice parameters and vocal status ratings, with the hypothesis that larger (a virtual lecture hall and theater compared to an office) and more full virtual rooms (75% of the capacity compared to 45%) would result in changes to the voice parameters and vocal status ratings. METHODS: Voice production from 30 vocally healthy participants was recorded in six virtual reality conditions. After each condition, the participants provided vocal status ratings. The voice recordings were processed to calculate mean and standard deviation of sound pressure level and fundamental frequency, mean pitch strength, time dose, and cepstral peak prominence smoothed. The effects of the virtual reality conditions on these voice acoustic parameters and the vocal status ratings were analyzed. RESULTS: The full virtual reality rooms resulted in significantly higher vocal fatigue and vocal discomfort ratings. The larger virtual reality rooms were significantly related to increases in mean and the standard deviation of sound pressure level, mean pitch strength, and cepstral peak prominence smoothed. CONCLUSIONS: This study demonstrated that visual size and visual fullness input during speech tasks have distinct effects on voice production and self-reported vocal status. Visual size is related to voice acoustic outcomes, while visual fullness is related to self-reported outcomes.

Acoustic-Perceptual Correlates of Voice Among Steam Train Engineers: Effects of Noise and Hearing Protection.

Occupational voice users are at a higher risk for developing voice disorders due to their vocal demands, such as prolonged periods of work-related voice use and nonideal environmental factors, such as speaking above background noise. The current study focused on the effects of background noise and hearing protection on acoustic-perceptual correlates of voice among steam train engineers. Fourteen participants phonated vowel /a/, read a phrase, and described a map under different noise and hearing protection conditions. Relative sound pressure level, relative fundamental frequency, and perceived vocal effort and disturbance decreased in the presence of hearing protection for all noise conditions. In contrast, these acoustic measures increased in the absence of hearing protection supporting Lombard effect. Overall, results of the current study provide insight into possible risks to vocal health in workers exposed to high levels of background noise and use hearing protection.

The Effects of Room Acoustics on Self-reported Vocal Fatigue: A Systematic Review.

PURPOSE: The main objective of the present systematic review is to quantify the relationship between the room acoustics and self-reported vocal fatigue. METHODS: A comprehensive literature search and systematic review were conducted using PubMed/MEDLINE, Science Direct, Web of Science, EBSCO, and Scopus databases. Two inclusion criteria were defined: (1) description of a relationship between the room acoustics and self-reported vocal fatigue; and (2) reporting of raw data and/or a statistic of the association between the variables. Risk of bias in the included studies was assessed via the Quality Assessment Tool for Quantitative Studies Effective Public Health Practice Project. The occurrences and frequencies of the most common parameters in the literature are presented, and a quantitative summary of their relationships is reported. RESULTS: In total, 12 publications met the inclusion criteria. The most relevant measures of self-reported vocal fatigue were the Vocal Fatigue Index (n = 3), Vocal Signs and Symptoms Questionnaire (n = 1), and vocal fatigue visual analog scales (n = 2). The most relevant room acoustic parameters include noise conditions (n = 6) and reverberation time (n = 2). The relationships between the room acoustic parameters and self-reported vocal fatigue are quantified and reported while maintaining the concepts stated in the original articles and outlining their similarities. CONCLUSION: Overall, background noise and reverberation time were determined to be the most significant independent variables associated with self-reported vocal fatigue. A primary limitation of the evidence was inconsistent measures of self-reported vocal fatigue.