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Purpose: Good verbal signals and low background noise are key factors for all children to maximize understanding of what is being taught. Classroom shape, surroundings, and even furnishings change how the environment “sounds” and how speech is “heard” in the classroom. Classroom acoustics is perhaps one of the most important, but often least considered, factors when designing a classroom. This systematic review aimed to characterize the relationship between intelligibility of speech and room acoustics in elementary schools based on the available evidence. Method: Eligible studies were identified using two computerized databases: PubMed and Scopus. In total, 23 publications met our inclusion criteria: (a) Participants must have been from elementary schools, (b) acoustic characterization of the classroom must have been provided, (c) intelligibility tests must have been performed, and (d) articles were written in English. Results: After identifying the parameters and tests used to quantify the intelligibility of speech, the speech intelligibility scores were analyzed in relation with acoustical parameters found in the articles, particularly signal-to-noise ratio and speech transmission index. Our results highlighted the negative effect on intelligibility associated with poor transmission of the speech and poor classroom acoustics caused by long reverberation times and high background noise. Conclusion: Good classroom acoustics is needed to improve speech intelligibility and, therefore, increase children's academic success.

This study explores sidetone amplification (amplified playback of one's own voice) provided via bone conduction in participants with voice disorders. The effects of bone conduction feedback on acoustic voice parameters and vocal effort ratings are examined.Speech samples of 47 participants with voice disorders were recorded in three auditory feedback conditions: two with sidetone amplification delivered via bone conduction and one condition with no alteration of the feedback. After each task, the participants rated their vocal effort on a visual analog scale. The voice recordings were evaluated by a speech-language pathologist through the GRBAS scale and processed to calculate the within-participant centered sound pressure level (SPL) values, the mean pitch strength (PS), the time dose (Dt%), and cepstral peak prominence smoothed (CPPS). The effects of the feedback conditions on these acoustic parameters and vocal effort ratings were analyzed.The high sidetone amplification condition resulted in a statistically significant decrease in the within-participant centered SPL values and mean pitch strength across all participants. The feedback conditions had no statistically significant effects on the vocal effort ratings, time dose (Dt%), or CPPS.This study provides an evidence that bone conduction sidetone amplification contributes to a consistent adaptation in the within-participant centered SPL values (ΔSPL) in patients with vocal hyperfunction, glottal insufficiency, and organic/neurological laryngeal pathologies compared to conditions with no feedback.

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.

Summary Background In addition to language differences in fundamental frequency between bilinguals and monolinguals, studies have also included other acoustic parameters to analyze differences in voice production associated with the language spoken. Aim To identify differences in voice acoustic parameters during English productions between monolingual and bilingual English speakers. Method Exploratory cross-sectional study with two groups of subjects: monolingual English speakers (n = 40), and bilingual English-Spanish speakers (n = 13). Participants filled out a questionnaire and recorded one reading in English (second sentence of Rainbow passage “The rainbow is a division of white light into many beautiful colors”) under a “virtual-simulated” acoustic condition of No Noise and Medium Reverberation Time (0.8 seconds). Result Analysis by gender shows that monolingual speakers had higher fundamental frequency mode, and lower standard deviation of fundamental frequency compared to bilingual English-Spanish speakers. Bilingual male speakers had higher jitter and harmonics-to-noise ratio than monolingual speakers. On the contrary, female bilingual speakers had lower jitter and shimmer than monolingual speakers. Conclusions Speaking a second language may influence voice acoustic parameters, and therefore, should be considered when comparing acoustic speech metrics.

Summary Objectives The goals of the study were to (a) examine vocal fatigue in speech-language pathology students through subjective and objective measures following a novel 30-minute vocal loading task (VLT) and (b) evaluate the effects of psychosocial factors on vocal fatigue. Methods Seventeen speech-language pathology students completed a 30-minute VLT using the LingWAVES software program. In addition to maintaining target intensity goals during reading a text, participants were also required to modify their pitch and voice quality. Vocal fatigue was measured subjectively using Vocal Fatigue Index and Borg vocal effort scale and objectively using variations of relative sound pressure level, fundamental frequency, pitch strength, smoothed cepstral peak prominence (CPPS), and acoustic voice quality index before, during, and after VLT. Participants provided information on their sleep quantity, stress, and depression through nonstandardized and standardized surveys. Results Results revealed that perceived effort and fatigue increased significantly after the 30-minute VLT. Acoustic measures of relative sound pressure level and fundamental frequency and increased systematically during and after the completion of task. All students were moderately stressed and measures related to pitch were highly related with perceived stress. Conclusions The results of this study provide support for altering multiple vocal parameters to induce measurable changes in vocal fatigue following a short-duration VLT.

Summary Introduction Computer analysis of voice recordings is an integral part of the evaluation and management of voice disorders. In many practices, voice samples are taken in rooms that are not sound attenuated and/or sound-proofed; further, the technology used is rarely consistent. This will likely affect the recordings, and therefore, their analyses. Objectives The objective of this study is to compare various acoustic outcome measures taken from samples recorded in a sound-proofed booth to those recorded in more common clinic environments. Further, the effects from six different commonly used microphones will be compared. Methods Thirty-six speakers were recorded while reading a text and producing sustained vowels in a controlled acoustic environment. The collected samples were reproduced by a Head and Torso Simulator and recorded in three clinical rooms and in a sound booth using six different microphones. Newer measures (eg, Pitch Strength, cepstral peak prominence, Acoustic Voice Quality Index), as well as more traditional measures (eg Jitter, Shimmer, harmonics-to-noise ratio and Spectrum Tilt), were calculated from the samples collected with each microphone and within each room. Results The measures which are more robust to room acoustic differences, background noise, and microphone quality include Jitter and smooth cepstral peak prominence, followed by Shimmer, Acoustic Voice Quality Index, harmonics-to-noise ratio, Pitch Strength, and Spectrum Tilt. Conclusions The effect of room acoustics and background noise on voice parameters appears to be stronger than the type of microphone used for the recording. Consequently, an appropriate acoustical clinical space may be more important than the quality of the microphone.

PurposeThe purpose of this document is threefold: (a) review the uses of the terms “vocal fatigue,” “vocal effort,” “vocal load,” and “vocal loading” (as found in the literature) in order to track the occurrence and the related evolution of research; (b) present a “linguistically modeled” definition of the same from the review of literature on the terms; and (c) propose conceptualized definitions of the concepts.MethodA comprehensive literature search was conducted using PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scientific Electronic Library Online. Four terms (“vocal fatigue,” “vocal effort,” “vocal load,” and “vocal loading”), as well as possible variants, were included in the search, and their usages were compiled into conceptual definitions. Finally, a focus group of eight experts in the field (current authors) worked together to make conceptual connections and proposed consensus definitions.ResultsThe occurrence and frequency of “vocal load,” “vocal loading,” “vocal effort,” and “vocal fatigue” in the literature are presented, and summary definitions are developed. The results indicate that these terms appear to be often interchanged with blurred distinctions. Therefore, the focus group proposes the use of two new terms, “vocal demand” and “vocal demand response,” in place of the terms “vocal load” and “vocal loading.” We also propose standardized definitions for all four concepts.ConclusionThrough a comprehensive literature search, the terms “vocal fatigue,” “vocal effort,” “vocal load,” and “vocal loading” were explored, new terms were proposed, and standardized definitions were presented. Future work should refine these proposed definitions as research continues to address vocal health concerns.

Noisy classrooms with poor acoustics decrease children’s speech understanding and comprehension. The signal quality is also often degraded by voice disorders that have a prevalence of 60% among teachers. Emerging evidence demonstrates that cognitive factors such as working memory (WM), attention, and inhibitory control (IC) also mediate children’s ability to recognize speech in noise. Speech intelligibility and comprehension tests were performed in a sound-proof booth with xx normal-hearing elementary students. The vocal material was recorded by an actor with normal and mimicked dysphonic voice. Babble noise was added to obtain 2 signal-to-noise (SNR) ratios at 0 and −12 dB. The test was administered using Qualtrics to collect intelligibility and comprehension scores, and measure response time to evaluate listening effort. Children’s WM and IC were also evaluated to explain individual differences. Results showed a statistically significant decrease in performance and increase in response time for the highest SNR and the dysphonic voice with a more detrimental effect on comprehension. This research determined how listening comprehension interacts with speech recognition and cognitive factors in children, providing pilot data to examine the variability of students' learning experience in classrooms when auditory input is degraded by poor acoustics and poor voice quality.

The purpose of this project is to assess the acoustical conditions in which optimal intelligibility and low listening effort can be achieved in real classrooms for elementary students, taking into consideration the effects of dysphonic voice and typical classroom noise. Speech intelligibility tests were performed in classrooms with 80 normal-hearing students (7–11 years old). The speech material was produced by a female actor using a normal voice quality and simulating a dysphonic voice. The stimuli were played by a Head and Torso Simulator. Child babble noise and classrooms with different reverberation times were used to obtain a Speech Transmission Index range from 0.2 to 0.7. The results showed a significant decrease in intelligibility when the speaker was dysphonic, in STI higher than 0.33. The rating of listening difficulty showed a significantly greater effort in perceiving the dysphonic voice. Younger children showed poorer performance and greater listening difficulty compared to older children when listening to the normal voice quality. Both groups were equally impacted when the voice was dysphonic. The results suggested that better acoustic conditions are needed for children to reach a good level of intelligibility and to reduce listening effort if the teacher is suffering from voice problems.

While the acoustic design of concert halls and other performance venues has evolved over time, the fact remains that the acoustic environments are generally designed for the benefit of the listening audiences rather than that of the performers. However, singers adapt their voice to room acoustics. This paper expands upon our current understanding of how a room’s acoustic environment influences a singer’s performance from the perceptions, observations, and lived experiences of performers. The subjects were nine classically-trained singers. Subjects sang the same aria in five different performance venues. After the performance, the singers filled out a questionnaire. Questions were subdivided into five major sections that were designed to capture their perceptions of (1) overall impressions; (2) background noise levels; (3) voice support; (4) Voice clarity. It was observed the overall impression of the room was mostly correlated with STv and IACClate. The perception of reverberation and the noisiness were correlated with C80 and EDT. The perceived voice support and clarity were mostly correlated with STv. This finding indicates the importance of auditory feedback in singers’ performance and the need for an acoustical design that takes into account the performers perception.

This study explores the influence of visual input on voice production in virtual reality with healthy participants. The effects of the size and fullness of various virtual rooms on acoustic voice parameters and self-reported vocal status ratings are examined. Speech samples from healthy participants were recorded in six virtual conditions. After each condition, the participants provided subjective vocal status ratings on visual analog scales. The voice recordings were processed to calculate objective voice acoustic parameters including sound pressure level, standard deviation of fundamental frequency, mean pitch strength, time dose, and cepstral peak prominence smoothed. The effects of the virtual reality conditions on these acoustic parameters and the vocal status ratings were analyzed. The largest virtual room resulted in significantly higher (worse) vocal status ratings. The size of the virtual rooms had statistically significant effects on mean pitch strength and cepstral peak prominence smoothed, among associations with other objective voice acoustic parameters. This study provides evidence that larger and more full virtual rooms contribute to higher (worse) vocal status ratings and changes in objective voice parameters in healthy speakers.

Voice dosimeters are useful tools for gathering voice production data in the daily lives of individuals with voice disorders. In this tutorial, instructions for a low-cost (less than $100), easy-to-assemble voice dosimeter are provided. This do-it-yourself (DIY) voice dosimeter is validated based on performance results. The DIY voice dosimeter was worn by 10 vocally healthy participants. The participants produced a sustained /a/ vowel and then 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 these two quantities as measured by the DIY dosimeter was performed by simultaneously comparing signals acquired through the reference microphone and the dosimeter themselves. 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 0.34Hz for females and males, respectively. The mean error and uncertainties for the DIY voice dosimeter are comparable to the most accurate voice dosimeters that were previously on the market.

The Word Intelligibility by Picture Identification (WIPI) test is a widely used test to assess speech recognition in the pediatric population. The test consists of four 25-item monosyllabic word lists that are within the vocabulary of preschool children. The child responds to each item by selecting one of six pictures on a page, one being the test item. The purpose of this study was to understand if the final score of a test can be obtained accurately with a fewer number of items in a word list. Ten monolingual children (8–12 yrs) with normal hearing were tested using a revised version of the WIPI (2nd ed.), presented in a soundbooth over headphones. Target words were presented in a classroom-noise masker at a fixed signal-to-noise ratio. The results suggest that a minimum of seven items is needed to obtain results that are not statistically different from the one complete test (25 items). This implies that the WIPI can be administered in a shorter time period, which could be particularly beneficial when testing multiple acoustic conditions on experimental tasks.

Humans “automatically” make vocal and speech adjustments in response to room acoustics; however, it is unclear whether these adjustments require additional cognitive load. Beyond this automatic adjustment, speakers may have to employ a speech production technique to enhance their intelligibility in situations such as public speaking. How does room acoustics challenge speakers on such occasions? Understanding the relationship between room acoustics, speech production, and cognitive load has practical implications for various areas, including speech training and room design. This study describes the associated change in cognitive load when speaking with and without a speech production technique at three levels of reverberation time (i.e., 0.05 s, 1.2 s, and 1.83 s at 125 Hz). Ten adult native speakers of American English were asked to read sentences in simulated acoustic environments using two types of speech production: habitual speech and clear speech, an intelligibility-enhancing technique. Cognitive load during the speech tasks was monitored with pupillometry and a subjective self-rating scale. Participants’ speech production behaviors were acoustically assessed via speech rate and alpha ratio. Preliminary results indicate that reverberation time significantly affects speech production behaviors and cognitive load and that the pattern of cognitive response varies substantially among the speakers.

The Lombard Effect is an increase in vocal effort in response to rising noise levels and disturbance in the communication environment. The objective of this study is to evaluate the Lombard Effect during four intensity levels from 45dB(A) to 75dB(A) of low-frequency, medium-frequency, and high-frequency energy noise to measure the effect of disturbance and vocal discomfort on the speaker’s intent to communicate, as well as the effect on speech intelligibility. Twelve conditions were randomly presented and recorded for each participant with the three types of noise and levels. At each condition, 20 participants were asked to read a passage. Immediately following each reading, participants were asked to rate the amount of noise disturbance and vocal comfort they had experienced. After, the speech intelligibility was evaluated by asking the participants to repeat the sentences of the QuickSin test emitted by a Head and Torso Simulator. The medium-frequency energy noise showed the highest Lombard Effect and the stronger decrease in intelligibility. In the conditions with noise with mid-frequency energetic content, the decrease in intelligibility was drastic with the increase in noise level. Low-frequency noises minimally impact speech intelligibility. High-frequency noises show little change in intelligibility with the increase in noise level.

Normal hearing listeners rely on their binaural auditory system to combine signals from both ears into single auditory objects, which aids source segregation and sound localization. The ability to combine signals from the two ears is influenced by interaural symmetry - the similarity of the place of stimulation along the left and right cochlea—and the interaural cross-correlation (ICC) of the signal, calculated as the peak correlation between the signal for the two ears across unilateral temporal offsets. The ability of bilateral cochlear implant (CI) users to combine signals from the two ears can be worse than that of NH listeners. This is partly attributed to decreases in interaural symmetry related to factors such as differences in electrode array insertion depth. A secondary effect of interaural asymmetry is that it can result in reduced ICC at interaurally symmetric locations, mediated by aspects of CI processing. This study aims to investigate how CI processing and interaural asymmetry affect the ICC available to CI users for interaurally symmetric locations, using electrodograms recorded from a CI processor placed on a Knowles Electronics Manikin for Acoustic Research (KEMAR). Inferences on how ICC is altered with interaural asymmetry for CI users will be discussed.

Background Speaking a second language influences jitter and shimmer when comparing monolingual English speakers with bilingual English-Spanish speakers. However, there is little information about differences on voice acoustic parameters when comparing monolingual Spanish speakers with bilingual Spanish-English speakers during their productions in Spanish. Aim Determine differences in five voice acoustic parameters commonly used in voice assessments (fundamental frequency, jitter, shimmer, Harmonics-to-Noise Ratio and Cepstral Peak Prominence Smoothed) which may be influenced by bilingualism. Methods Exploratory cross-sectional study with two groups of female participants: monolingual Spanish speakers (n = 17), and bilingual Spanish-English speakers (n = 11). Participants filled out a questionnaire and recorded two voice samples (sustained vowel /a/ and reading). For this study, all the participants reported that their native language was Spanish. Results Being a female bilingual speaker had a significant effect on Shimmer (%) with a Beta = -0.7. Similar tendency was found on harmonics-to-noise ratio (B = 0.2) and cepstral peak prominence smoothed (B = 0.2). Conclusions Our results indicate that being a native Spanish female speaker, speaking English as a second language, has significant small effects on voice acoustic parameters, such as shimmer, harmonics-to-noise ratio and cepstral peak prominence smoothed, during their productions in Spanish. This information is of interest for assessment and intervention plans of bilingual speakers at clinical and work-related settings.

Summary Introduction Vocal loading tasks (VLTs) help researchers gather acoustic measurements and understand how a healthy speaker adjusts their voice in response to challenges. There is a dearth of evidence measuring the impact of speaking rate in VLTs on acoustic voice parameters and vocal fatigue. Objectives In the present study, the relationships between acoustic voice parameters and self-reported vocal fatigue were examined through an experimental VLT. Methods 38 students completed a 45-minute VLT which involved the recording of three randomized reading tasks. The tasks varied by the speed in which the words were presented (slow, medium, fast) on a computer monitor. Vocal fatigue ratings were measured subjectively using a Borg scale and negative adaptations to vocal loading were measured objectively using Sound Pressure Level (SPL, in dBA), fundamental frequency (fo, in semitones), and phonation time (Dt %). Results Analysis indicated that vocal fatigue increases with time, and the slope of this relationship is affected by the speaking rate. SPL and fo increased with speaking rate and the standard deviation of SPL and fo decreased with speaking rate. On average, the male participants’ phonation time values were 7.8% lower than the female participants. The rate of increase of vocal fatigue with time during the experiment was higher in the fast speaking style compared to the slow and medium ones. Conclusion The results provide support that the novel VLT altered multiple vocal parameters to induce measurable changes in vocal fatigue.

SUMMARY Aims (1) Determine the difference in vocal fry phonation in English and Spanish productions among bilingual young adults, (2) Characterize the effect of spoken language and native language on vocal fry production among English-Spanish bilingual speakers, (3) Identify the effect of first and second language knowledge of the listener in the voice perceptual assessment, and (4) Define the effect of the environment of the assessment (in situ vs. online), in the voice perceptual assessment. Method Exploratory cross-sectional study of 34 bilingual (Spanish-English) speakers and six inexperienced listeners. Participating speakers produced two speech samples (one in English and one in Spanish). Six inexperienced monolingual and bilingual listeners performed the voice perceptual assessment of vocal fry, General grade of hoarseness, and Roughness using a 4-point rating scale. Results Bilingual speakers used vocal fry more often when they were speaking in English (around 3%) compared with their production in Spanish (around 2%). Bilingual native English speakers used vocal fry more often during their productions in both languages compared with bilingual native Spanish speakers. Bilingual listeners had the highest agreement when identifying vocal fry in both languages. Conclusions Differences in production of vocal fry between native speakers of American English and native speakers of Spanish may be evidence of transferring of vocal behavior (such as vocal fry) from one language to the second one. In addition, being a bilingual listener may have an important effect on the perceptual identification of voice quality in English and Spanish, as well as vocal fry in English.

Objectives/hypothesis To investigate the relationship of throat pain and dysphonia. Study design Prospective cohort study. Methods Forty-five subjects presenting with hyoid bone syndrome (HBS) and dysphonia were asked to rate their pain on a numerical rating scale and complete the 10-item Voice-Related Quality of Life (V-RQOL) questionnaire prior to and at 1-week follow-up after treatment with triamcinolone injection into the attachments to the affected greater cornu(s). Wilcoxon signed-rank tests were applied to evaluate if the overall V-RQOL scores, the physical functioning (PF) and social-emotional (SE) domain scores, and pain scores changed significantly after treatment. To evaluate how change in perceived pain affected V-RQOL, the differences in the V-RQOL, PF, and SE domain scores, and in pain scores were calculated for each subject. Three linear models were fit to the response variables, ΔV-RQOL, ΔPF, and ΔSE, using ΔPain as a predicting variable. Results V-RQOL, PF, and SE domain scores, and pain scores all improved significantly with treatment. A bigger decrease in the pain score led to a bigger increase in V-RQOL and domain scores, with slopes varying between -1.1 and -1.4. The PF domain scores showed the greatest improvement with decrease in pain scores. Conclusions Effective treatment of HBS led to improvement in patients' voice complaints, suggesting that throat pain may have a direct effect on voice. This may be related to compensatory perilaryngeal adjustments patients make when speaking with a "guarding" effect when they have throat pain. Level of evidence IV (Cohort study) Laryngoscope, 2021.

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.

Due to the recent pandemic event related to COVID-19, many countries are mandating the use of face masks to reduce the spread of the virus. Unfortunately, those masks can have a detrimental effect on speech communication, particularly for vulnerable listeners like children with hearing loss. This work investigates which type of face mask yields the highest level of speech intelligibility for children with cochlear implants. Fourteen children with cochlear implants aged 7–15 years have been involved, together with a control group of six normal-hearing children. Online speech intelligibility tests (simplified Italian matrix sentence test) were performed testing different masks at different signal to noise ratios. The listening difficulty was also evaluated on a 5-points scale. The results of this study showed which type of face masks are recommended to maximize intelligibility for children with cochlear implants.

Singers perform in various acoustic environments; however, how the environments affect their mental effort is poorly understood. This study virtually simulated acoustic environments to examine the effect of reverberation time on singers’ vocal behaviors and mental effort. Participants were five vocally healthy singers who completed a minimum of undergraduate-level training. For the virtual environments, the voice signal was digitally processed by adding reverberation using a real-time effect processor of the digital mixer. The processed sound was played back to the participant using open headphones. The average T30 was 1.13 s in Low T30 condition, 1.39 s in Medium T30 condition, and 1.90 s in High T30 condition. Participants sang the American national anthem and rated their perceived level of overall effort, mental effort, physical effort, frustration, and performance using a modified NASA-TLX scale for each acoustic condition. Pupillometry was also used to measure the mental effort during each task. Their voice recordings were acoustically analyzed for intensity, singing-power ratio, alpha ratio, pitch accuracy, and vibrato rate and extent. The presentation will discuss: (1) individual differences in the participants’ response to the reverberation time and (2) the degree of agreement between the subjective rating and physical measurement of mental effort.

Summary Introduction The Lombard effect (LE) is a phenomenon in which speakers adjust their vocal production by raising the volume in noisy environments. As a result, the LE can create problems of vocal strain, fatigue and potential injury. Objectives This study aims to examine the difference in vocal intensity output in subjects wearing unilateral hearing protection versus no hearing protection in the presence of background noise. Methods Each subject was seated inside a sound booth wearing a head-mounted microphone. Subjects were asked to read an excerpt from “The Rainbow Passage” while various levels of background noise were played: 50, 60, 70, and 80 dBA (Multitalker Babble). Each noise level was played while the subject was with and without unilateral ear protection (Optime 98 Earmuff [3M]) in random order. The earmuff has a noise reduction rating of 25 dB. After each reading of the text, subjects were asked to rate communication disturbance, vocal clarity, and discomfort during talking using a 10 cm visual analogue scale. Results The LE is reduced from 0.38 dB/dB to 0.29 dB/dB with unilateral ear occlusion. However, self-perception of disturbance, clarity and comfort were not affected by unilateral occlusion, only by noise level. Conclusions Unilateral hearing protection reduces the LE and may protect against phonotrauma when speaking in an environment with loud background noise.

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.

This study explored the effects of wearing face masks on classroom communication. We evaluated the effects of three different types of face masks (fabric, surgical and N95 masks) on speech intelligibility presented to college students in auralized classrooms. 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 fabric masks yielded significantly greater reduction in speech intelligibility compared to the other masks. Therefore, surgical masks or N95 masks are strongly recommended in teaching environments.

Purpose Vocal instructors during their normal workday are exposed to high noise levels that can affect their voice and hearing health. The goal of this study was to evaluate the voice and hearing status of voice instructors before and after lessons and relate these evaluations with voice and noise dosimetry taken during lessons. Methods Eight voice instructors volunteered to participate in the study. The protocol included (1) questionnaires, (2) pre/post assessment of voice quality and hearing status, and (3) voice and noise dosimetry during lessons. Acoustic measurements were taken of the unoccupied classrooms. Results In six of eight classrooms, the measured noise level was higher than the safety recommendations set by National Institute for Occupational Safety and Health. The background noise level and the reverberation time in the classrooms were in compliance with the national standard recommendations. We did not find a clear pattern comparing pre- and post-measurements of voice quality consistent among genders. In all subjects, the Sound Pressure Levels mean increased, and the standard deviation of fundamental frequency decreased indicating association to vocal fatigue. Previous studies link these changes to increasing vocal fatigue. The audiometric results revealed seven out of eight instructors have sensorineural hearing loss. Conclusions The interaction of the acoustic space and noise levels can contribute to the development of hearing and voice disorders for voice instructors. If supported by larger sample size, the results of this pilot study could justify the need for a hearing and voice conservation program for music faculty.

PURPOSE: To explore the short-term effect of work-related voice use on voice function, and noise exposure on hearing function among radio broadcasters. METHOD: A one-week follow-up study with the participation of two radio broadcasters was conducted. Participants were monitored at the beginning and at the end of the working week. Pre-monitoring assessment on Monday (baseline measure) and post-monitoring assessment on Friday (follow-up measure) were performed to identify short-term effects of work-related conditions on voice and hearing function among radio broadcasters. RESULT: Changes in fundamental frequency post-monitoring at the end of the work week may be an indication of work-related vocal fatigue. Changes in the distribution and standard deviation of SPL during the monitoring from Monday to Friday may indicate control of the vocal loudness as a strategy to reduce vocal effort during broadcasting. During a one-week follow-up, noise conditions during radio broadcasting were below occupational exposure limits and without noticeable consequences on hearing function. CONCLUSION: The work-related communicative profile of radio broadcasting, from this pilot study, suggests that although vocal demands in terms of vocal load may differ among broadcasters, the work-related conditions of broadcasting may play a role on vocal function among these occupational voice users. Concerning hearing function, our results indicate that occupational noise exposure be represented minimal risk for hearing problems but the consequences of long-term noise exposure on hearing mechanisms may yet occur. Future studies with bigger sample sizes are warranted to confirm our results.

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.

In both practicing audiology and speech language pathology, as well as in speech and hearing science research, the space where the work is done is an integral part of the function. Hence, for all of these endeavors it can be important to measure the acoustics of a room. This article provides a tutorial regarding the measurement of room reverberation and background noise, both of which are important when evaluating a space’s strengths and limitations for speech communication. As the privacy of patients and research participants is a primary concern, the tutorial also describes a method for measuring the amount of acoustical insulation provided by a room’s barriers. Several room measurement data sets – all obtained from the assessment of clinical and research spaces within our own department – are presented here as examples.

Summary Introduction In classical singing techniques, it is common to manipulate the vocal tract to channel airflow to increase voice quality and volume. Technique varies according to the style of the music, the voice type, and range of a given singer. Although these practices are intentional, fixed physiological aspects of a singer's vocal instrument also play an extremely impactful role in determining voice quality. Objectives In the present study, the relationship between the dimensions of the maxillary dental arch and voice quality were examined in professional singers. Methods The dimensions of the palate were measured from the maxillary dental casts of 14 female singers. Audio recordings were made for the same participants while singing a sustained /a/ singing vowel, a glissando, the song "Are You Sleeping", and a selected song from their personal repertoire. The dimensions of the palate were measured from maxillary dental casts. From the recordings, two parameters were calculated: (1) the Singing Power Ratio (SPR) and (2) A2 A1 ratio. Higher SPR values indicate a stronger ring in the voice, typical of operatic singing style, while higher A2 A1 ratio values are associated with the belting singing style. Results Singers with larger frontal palate depth, smaller posterior palate depth, larger frontal palate width, and smaller posterior palate width seem to be more suitable for an operatic singing style. Singers who had larger overall depth and width of the palate measurements produced an increased second harmonic, typical of the belting style. Conclusions When considering a singer's ability to produce vocalizations successfully, physiological structure is an increasingly important factor. The present study discovered that palate depth and width are associated with statistically significant differences in SPR and A2/A1 parameters. These parameters correlate with two styles of singing, operatic, and belting respectively.

Voice disorders can reduce speech intelligibility. This study evaluated the effect of noise, voice disorders, and room acoustics on vowel intelligibility. College students listened to 9 vowels in /h/-V-/d/ format. The speech was recorded by three adult females with dysphonia and three adult females with normal voice quality. The recordings were convolved with three oral-binaural impulse responses with 0.4 s, 0.7 s, and 3.1 s of reverberation time. The test was performed online. The intelligibility and the listening easiness were significantly higher when the speakers had normal voice quality and in low reverberated environments.

Noise generated from human activities (in particular by infrastructure and construction sites) can have a strong impact on the physiology and behavior of birds. In this work, a quantitative method for evaluating the impact of noise on wild birds is proposed. The method combines the results of previous studies that considered the effect of noise on birds and involved noise mapping evaluations. A forecast noise simulation was used to generate maps of (1) signal masking areas and (2) potential density variation. These results allow the determination of the highest risk areas for wild birds.