Calibration of Clinical Audio Recording and Analysis Systems for Sound Intensity Measurement

Toward Sham Interventions for Behavioral Voice Treatment Outcome Research in Female Students Without Dysphonia

OBJECTIVES/HYPOTHESIS

To develop sham voice treatment techniques to be used in voice treatment outcome research, and to investigate their effectiveness as sham. This entails that the techniques induce no changes in voice or voice physiology, yet still lead to a perception of efficacy.

STUDY DESIGN

Prospective randomized blinded controlled study.

METHODS

Three distinct sham intervention protocols (SIPs) were conceptualized as placebic comparators for three common voice treatment approaches with focus on vocalization (SIP1), respiration (SIP2), and manipulation (SIP3). Forty-eight female students participated in the study. Each participant attended ten 30-minute sessions over 5weeks, including a baseline evaluation, three sessions of one SIP, an inter-SIP voice assessment, three sessions of a second SIP, and a final post-SIP assessment. Auditory-perceptual and instrumental voice evaluations were used as voice treatment outcome measures. The participants' perception of voice-related quality of life was evaluated using the French Voice Handicap Index (VHIFR). Frequentist as well as Bayesian statistical methods were applied for group comparisons. The effects of combining two SIPs, the potential influence of SIP order, and experimenter/clinician effects, were also investigated.

RESULTS

The respiration-based SIP2 showed changes only in sound intensity level on a sustained vowel across the three sham intervention sessions. In contrast, the vocalization-based SIP1 impacted sound intensity level on a sustained vowel, sound intensity level on read text, and maximum phonation time. The manipulation-based SIP3 affected smoothed cepstral peak prominence on read text, Acoustic Voice Quality Index, and Dysphonia Severity Index. SIP2 thus demonstrated the highest alignment with the study's objectives, followed by SIP1 and SIP3. GRBASI ratings revealed no statistical differences for any SIP. VHIFr decreased significantly after all three SIPs. Combining the SIPs generally replicated the effects observed when each SIP was used individually. There was no order effect or experimenter/clinician effect on the results.

CONCLUSIONS

This study demonstrated significant changes in participants' perceived voice quality (measured with VHIFr) across various SIPs, despite minimal impact on objective voice function measures. Further investigation is necessary to establish one or more protocols as genuinely sham interventions.

Mandarin-speaking Children With Cochlear Implants Face Challenges in Using F0 Expansion to Express Contrastive Focus

OBJECTIVES

Children with cochlear implants (CIs) face challenges in perceiving fundamental frequency (F0) information because CIs do not transmit F0 effectively. In Mandarin, F0 can contrast meanings at the word level, that is, via lexical tones with distinct F0 contours, and signal contrastive relations between words at the utterance-level, that is, via contrastive focus with expanded F0 range and longer duration. Mandarin-speaking children with CIs have been reported to face challenges in producing distinct F0 contours across tones, but early implantation facilitates tonal acquisition. However, it is still unclear if utterance-level prosody, such as contrastive focus, is also challenging for these children, and if early implantation also offers benefits for focus production. Therefore, this study asked how accurately children with CIs can produce contrastive focus, and if early implantation leads to more accurate focus production, with acoustic patterns approaching that of children with typical hearing (TH).

DESIGN

Participants included 55 Mandarin-speaking children (3 to 7 years) with CIs and 55 age-matched children with TH. Children produced noun phrases with and without contrastive focus, such as RED-COLORED cat versus red-colored cat . Three adult native listeners perceptually scored the productions as correct or incorrect. The "correct" productions were then acoustically analyzed in terms of F0 range and duration.

RESULTS

Based on the perceptual scores, children with CIs produced focus with significantly lower accuracy (38%) than their TH peers (84%). The acoustic analysis on their "correct" productions showed that children with TH used both F0 and duration to mark focus, producing focal syllables with an expanded F0 range and long duration, and postfocal syllables with a reduced F0 range and short duration. However, children with CIs differed from children with TH in that they produced focal syllables with long duration but not an expanded F0 range, although they produced postfocal syllables with a reduced F0 range and short duration like their TH peers. In addition, early implantation correlated with the percept of more accurate focus productions and better use of F0 range in focal marking.

CONCLUSIONS

This study finds that Mandarin-speaking children with CIs are still learning to apply appropriate acoustic cues to contrastive focus. The challenge appears to lie in the use of an expanded F0 range to mark focus, probably related to the limited transmission of F0 information through the CI devices. These findings thus have implications for parents and those working with children with CIs, showing that utterance-level prosody also requires speech remediation, and underscores the critical role of identifying problems early in the acquisition of F0 functions in Mandarin, not only at the word level but also at the utterance-level.

Effect of Face Masks on Voice Quality Associated with Young and Older Chinese Adult Speakers

OBJECTIVES

Face masks have become important after the pandemic, but the change in voice when wearing a face mask is still unclear. The study investigated the effect of face masks on the acoustic and perceptual characteristics of voice quality associated with young and older Chinese adults.

METHODS

Voice samples of the sustained vowel /a/ and continuous speech produced by 44 older and 61 young adults with and without an ASTM level-3 surgical face mask were recorded and analyzed. Perceptual and acoustic parameters including mean fundamental frequency (F0) and intensity, perturbation measures (jitter and shimmer), harmonic-to-noise ratio (HNR), smoothed cepstral peak prominence (CPPs), and long-term average spectrum (LTAS) measures were obtained and compared.

RESULTS

When comparing masked to unmasked voices, for both male and female speakers, F0 and intensity showed no significant changes, except for F0 of continuous speech, which increased significantly. Meanwhile, perturbation measures such as jitter and shimmer were reduced, while HNR and CPPs increased. In addition, LTAS measures included low-frequency mean spectral energy (MSE), high-frequency MSE, and spectral tilt (ST), which were different. For perceptual measures, the overall grade of dysphonia, and roughness were reduced, except for the breathiness among older male speakers, while the other vocal qualities were not changed. Between young and older speakers, significant differences in shimmer, CPPs, and perceived breathiness among male speakers, and low-frequency MSE among female speakers were found.

CONCLUSION

Wearing a surgical mask appeared to change the perceived voice quality. This is supported by the change in perturbation and LTAS measures, and HNR and CPPs values. In addition, some differences between young and older adults were observed. Oral Communication effectiveness may be affected when wearing surgical masks due to changes in voice quality. Additionally, clinicians need to exercise hightened caution in evaluating the voice quality of clients when wearing face masks.

The Relationship Between Voice Parameters and Speech Intelligibility: A Scoping Review

OBJECTIVE

To synthesize existing evidence of the relationship between voice parameters and speech intelligibility.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Review (PRISMA-ScR) guidelines, 13 databases were searched and a manual search was conducted. A narrative synthesis of methodological quality, study characteristics, participant demographics, voice parameter categorization, and their relationship to speech intelligibility was conducted. A Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment was also performed.

RESULTS

A total of 5593 studies were retrieved, and 30 eligible studies were included in the final scoping review. The studies were given scores of 10-25 (average 16.93) out of 34 in the methodological quality assessment. Research that analyzed voice parameters related to speech intelligibility, encompassing perceptual, acoustic, and aerodynamic parameters, was included. Validated and nonvalidated perceptual voice assessments showed divergent results regarding the relationship between perceptual parameters and speech intelligibility. The relationship between acoustic parameters and speech intelligibility was found to be complex and the results were inconsistent. The limited research on aerodynamic parameters did not reach a consensus on their relationship with speech intelligibility. Studies in which listeners were not speech-language pathologists (SLPs) far outnumbered those with SLP listeners, and research conducted in English contexts significantly exceeded that in non-English contexts. The GRADE evaluation indicated that the quality of evidence varied from low to moderate.

DISCUSSION

The results for the relationship between voice parameters and intelligibility showed significant heterogeneity. Future research should consider age-related voice changes and include diverse age groups. To enhance validity and comparability, it will be necessary to report effect sizes, tool validity, inter-rater reliability, and calibration procedures. Voice assessments should account for the validation status of tools because of their potential impact on the outcomes. The linguistic context may also influence the results.

Long-term Acoustic Effects of Gender-Affirming Voice Training in Transgender Women

OBJECTIVES

One role of a speech-language pathologist (SLP) is to help transgender clients in developing a healthy, gender-congruent communication. Transgender women frequently approach SLPs to train their voices to sound more feminine, however, long-term acoustic effects of the training needs to be rigorously examined in effectiveness studies. The aim of this study was to investigate the long-term effects (follow-up 1: 3months and follow-up 2: 1year after last session) of gender-affirming voice training for transgender women, in terms of acoustic parameters.

STUDY DESIGN

This study was a randomized sham-controlled trial with a cross-over design.

METHODS

Twenty-six transgender women were included for follow-up 1 and 18 for follow-up 2. All participants received 14weeks of gender-affirming voice training (4weeks sham training, 10weeks of voice feminization training: 5weeks pitch elevation training and 5weeks articulation-resonance training), but in a different order. Speech samples were recorded with Praat at four different time points (pre, post, follow-up 1, follow-up 2). Acoustic analysis included fo of sustained vowel /a:/, reading and spontaneous speech. Formant frequencies (F1-F2-F3) of vowels /a/, /i/, and /u/ were determined and vowel space was calculated. A linear mixed model was used to compare the acoustic voice measurements between measurements (pre - post, pre - follow-up 1, pre - follow-up 2, post - follow-up 1, post - follow-up 2, follow-up 1 - follow-up 2).

RESULTS

Most of the fo measurements and formant frequencies that increased immediately after the intervention, were stable at both follow-up measurements. The median fo during the sustained vowel, reading and spontaneous speech stayed increased at both follow-ups compared to the pre-measurement. However, a decrease of 16 Hz/1.7 ST (reading) and 12 Hz/1.5 ST (spontaneous speech) was detected between the post-measurement (169 Hz for reading, 144 Hz for spontaneous speech) and 1year after the last session (153 Hz and 132 Hz, respectively). The lower limit of fo did not change during reading and spontaneous speech, both directly after the intervention and during both follow-ups. F1-2 of vowel /a/ and the vowel space increased after the intervention and both follow-ups. Individual analyses showed that more aspects should be controlled after the intervention, such as exercises that were performed at home, or the duration of extra gender-affirming voice training sessions.

CONCLUSIONS

After 10 sessions of voice feminization training and follow-up measurements after 3months and 1year, stable increases were found for some formant frequencies and fo measurements, but not all of them. More time should be spent on increasing the fifth percentile of fo, as the lower limit of fo also contributes to the perception of more feminine voice.

Acoustic and Perceptual Effects of Articulation Exercises in Transgender Women

PURPOSE

This study measured the impact of articulation exercises using a cork and articulation exercises for lip spreading on the formant frequencies of vowels and listener perceptions of femininity in transgender women.

METHODS

Thirteen transgender women were recorded before and after the cork exercise and before and after the lip spreading exercise. Speech samples included continuous speech during reading and were analyzed using Praat software. Vowel formant frequencies (F1, F2, F3, F4, F5) and vowel space were determined. A listening experiment was organized using naïve cisgender women and cisgender men rating audio samples of continuous speech. Masculinity/femininity, vocal quality and age were rated, using a visual analogue scale (VAS).

RESULTS

Concerning vowel formant frequencies, F2 /a/ and F5 /u/ significantly increased after the lip spreading exercise, as well as F3 /a/, F3 /u/ and F4 /a/ after the cork exercise. The lip spreading exercise had more impact on the F2 /a/ than the cork exercise. Vowel space did not change after the exercises. The fundamental frequency (fo) increased simultaneously during both exercises. Both articulation exercises were associated with significantly increased listener perceptions of femininity of the voice.

CONCLUSION

Subtle changes in formant frequencies can be observed after performing articulation exercises, but not in every formant frequency or vowel. Cisgender listeners rated the speech of the transgender women more feminine after the exercises. Further research with a more extensive therapy program and listening experiment is needed to examine these preliminary findings.

Are smartphones and low-cost external microphones comparable for measuring time-domain acoustic parameters?

PURPOSE

This study examined and compared the diagnostic accuracy and correlation levels of the acoustic parameters of the audio recordings obtained from smartphones on two operating systems and from dynamic and condenser types of external microphones.

METHOD

The study included 87 adults: 57 with voice disorder and 30 with a healthy voice. Each participant was asked to perform a sustained vowel phonation (/a/). The recordings were taken simultaneously using five microphones AKG-P220, Shure-SM58, Samson Go Mic, Apple iPhone 6, and Samsung Galaxy J7 Pro microphones in an acoustically insulated cabinet. Acoustic examinations were performed using Praat version 6.2.09. The data were examined using Pearson correlation and receiver-operating characteristic (ROC) analyses.

RESULTS

The parameters with the highest area under curve (AUC) values among all microphone recordings in the time-domain analyses were the frequency perturbation parameters. Additionally, considering the correlation coefficients obtained by synchronizing the microphones with each other and the AUC values together, the parameter with the highest correlation coefficient and diagnostic accuracy values was the jitter-local parameter.

CONCLUSION

Period-to-period perturbation parameters obtained from audio recordings made with smartphones show similar levels of diagnostic accuracy to external microphones used in clinical conditions.

Test-Retest Reliability of the Acoustic Voice Quality Index and the Acoustic Breathiness Index

OBJECTIVE

The acoustic voice quality index (AVQI) and the acoustic breathiness index (ABI) are two validated measurements for the objective-acoustic assessment of voice quality. The aim of this study was to evaluate the relative and absolute reliability of AVQI and ABI as well as detect the natural variability of vocally-healthy voices.

METHODS

Totally, 39 vocally-healthy participants received weekly an AVQI- and ABI measurement using the freeware VOXplot over a period of 3 weeks. This study is a within-subject design to assess significant differences between the test and retest measurements (test and mean of two retests) of AVQI and ABI with the paired sample t test and to investigate the reliability of these two acoustic parameters with the intraclass correlation coefficient (ICC), Bland-Altman plot, and the minimal detectable change (MDC).

RESULTS

No significant differences between the test-retest measurements of AVQI and ABI were revealed (all P-values > 0.05). The relative reliability of AVQI and ABI showed good results (eg, ICC = 0.81, and ICC = 0.92, respectively). Absolute reliability measured with the MDC yielded a test-retest value of 0.78 and 0.66 for the AVQI and ABI, respectively. Deviations within this range may be due to natural variations of the voice (random bias).

CONCLUSION

AVQI and ABI revealed high-reliability results in a test-retest measurement of vocally-healthy participants.

Impact of naturalistic smartphone positioning on acoustic measures of voicea)

Smartphone technology has been used for at-home health monitoring, but there are few available applications (apps) for tracking acoustic measures of voice for those with chronic voice problems. Current apps limit the user by restricting the range of smartphone positions to those that are unnatural and non-interactive. Therefore, we aimed to understand how more natural smartphone positions impacted the accuracy of acoustic measures in comparison to clinically acquired and derived measures. Fifty-six adults (11 vocally healthy, 45 voice disordered, aged 18-80 years) completed voice recordings while holding their smartphones in four different positions (e.g., as if reading from the phone, up to the ear, etc.) while a head-mounted high-quality microphone attached to a handheld acoustic recorder simultaneously captured voice recordings. Comparisons revealed that mean fundamental frequency (Hz), maximum phonation time (s), and cepstral peak prominence (CPP; dB) were not impacted by phone position; however, CPP was significantly lower on smartphone recordings than handheld recordings. Spectral measures (low-to-high spectral ratio, harmonics-to-noise ratio) were impacted by the phone position and the recording device. These results indicate that more natural phone positions can be used to capture specific voice measures, but not all are directly comparable to clinically derived values.

Potentially Inadequate Real-Life Speech Levels by Healthcare Professionals during Communication with Older Inpatients

BACKGROUND

The aim of this study was to investigate real-life speech levels of health professionals during communication with older inpatients in small group settings.

METHODS

This is a prospective observational study assessing group interactions between geriatric inpatients and health professionals in a geriatric rehabilitation unit of a tertiary university hospital (Bern, Switzerland). We measured speech levels of health professionals during three typical group interactions (discharge planning meeting (n = 21), chair exercise group (n = 5), and memory training group (n = 5)) with older inpatients. Speech levels were measured using the CESVA LF010 (CESVA instruments s.l.u., Barcelona, Spain). A threshold of <60 dBA was defined as a potentially inadequate speech level.

RESULTS

Overall, mean talk time of recorded sessions was 23.2 (standard deviation 8.3) minutes. The mean proportion of talk time with potentially inadequate speech levels was 61.6% (sd 32.0%). The mean proportion of talk time with potentially inadequate speech levels was significantly higher in chair exercise groups (95.1% (sd 4.6%)) compared to discharge planning meetings (54.8% (sd 32.5%), p = 0.01) and memory training groups (56.3% (sd 25.4%), p = 0.01).

CONCLUSIONS

Our data show that real-life speech level differs between various types of group settings and suggest potentially inadequate speech levels by healthcare professionals requiring further study.

Voice Outcome of Glottoplasty in Trans Women

PURPOSE

This study investigates the short- and longer-term effects of glottoplasty up to six months after surgery on acoustic voice parameters, listener perceptions, and client's satisfaction in trans women. Secondly, the impact of chondrolaryngoplasty and voice therapy on the glottopasty outcomes was investigated.

METHOD

A prospective longitudinal non-controlled trial was used. Thirty-five trans women undergoing glottoplasty or a combination of glottopasty and chondrolaryngoplasty were included in this study. A voice assessment was conducted before surgery and 1 week, 1 month and 6 months after surgery. The following outcome parameters were measured: fundamental frequency (fo), intensity, frequency and intensity range, Dysphonia Severity Index (DSI), Acoustic Voice Quality Index (AVQI), Voice Handicap Index (VHI), Trans Woman Voice Questionnaire (TWVQ), and visual analogue scales (VAS) measuring client's satisfaction. Listener perceptions of masculinity-femininity were collected using a listening experiment.

RESULTS

Significant differences over time were found for all fo and intensity parameters, DSI, AVQI, VHI and TWVQ scores. Listener perception and self-perception of femininity was higher after surgery. Significant differences in evolution of listener perceptions were found between the groups with and without voice therapy.

CONCLUSION

Glottoplasty improves voice related quality of life and is an effective method to increase the fo and associated perceptual femininity. After glottoplasty an immediate and short-term decrease in voice quality, vocal capacity and frequency range was measured with a progressive recovery on the longer term. Long term side effects of glottoplasty are a reduction in speaking intensity and intensity range. Voice therapy seems to improve the outcomes of glottoplasty, but should be further investigated in future studies.

Short-Term Acoustic Effects of Speech Therapy in Transgender Women: A Randomized Controlled Trial

PURPOSE

This study measured and compared the acoustic short-term effects of pitch elevation training (PET) and articulation-resonance training (ART) and the combination of both programs, in transgender women.

METHOD

A randomized controlled study with cross-over design was used. Thirty transgender women were included and received 14 weeks of speech training. All participants started with 4 weeks of sham training; after which they were randomly assigned to one of two groups: One group continued with PET (5 weeks), followed by ART (5 weeks); the second group received both trainings in opposite order. Participants were recorded 4 times, in between the training blocks: pre, post 1 (after sham), post 2 (after training 1), and post 3 (after training 2). Speech samples included a sustained vowel, continuous speech during reading, and spontaneous speech and were analyzed using Praat software. Fundamental frequency (f _o), intensity, voice range profile, vowel formant frequencies (F _1-2-3-4-5 of /a/-/i/-/u/), formant contrasts, vowel space, and vocal quality (Acoustic Voice Quality Index) were determined.

RESULTS AND CONCLUSIONS

Fundamental frequencies increased after both the PET and ART program, with a higher increase after PET. The combination of both interventions showed a mean increase of the f _o of 49 Hz during a sustained vowel, 49 Hz during reading, and 29 Hz during spontaneous speech. However, the lower limit (percentile 5) of the f _o during spontaneous speech did not change. Higher values were detected for F _1-2 of /a/, F ₃ of /u/, and vowel space after PET and ART separately. F _1-2-3 of /a/, F _1-3-4 of /u/, vowel space, and formant contrasts increased after the combination of PET and ART; hence, the combination induced more increases in formant frequencies. Intensity and voice quality measurements did not change. No order effect was detected; that is, starting with PET or ART did not change the outcome.

Accuracy Analysis of the Multiparametric Acoustic Indices AVQI, ABI, and DSI for Speech-Language Pathologist Decision-Making

PURPOSE

To investigate the accuracy of the Acoustic Voice Quality Index (AVQI), the Acoustic Breathiness Index (ABI), and the Dysphonia Severity Index (DSI) for speech-language pathologist (SLP) decision-making in the evaluation of teachers' voice conditions.

METHODS

Cross-sectional observational study with a convenience sample composed of 21 teachers "fit" in carrying out their work activities as a teacher, and 21 considered "unfit" for the same. All teachers underwent a voice evaluation, carried out by a voice-specialized speech-language pathologist. Voice evaluation included the SLP's opinion on whether the teachers presented "fit" or "unfit" for work. The voice and speech samples used for the AVQI and ABI scores were the mid-three seconds of a sustained vowel /a/, and a spontaneous count from 1 to 10. The following parameters were used to extract the DSI score: mid-three seconds of a sustained vowel /a/, maximum phonation time of a sustained vowel /a/, ascending vocal glide on the vowel /a/ until reaching the highest pitch, and sustained vowel /a/ at the softest possible vocal intensity. The t-test was used to compare the difference between the AVQI and ABI indices. The Mann-Whitney test was used for the DSI index, with a confidence level of 95%. The receiver operating characteristic curve (ROC) was used for accuracy analysis.

RESULTS

There was a difference in AVQI values (P=0.008), ABI (P=0.014), and DSI (P=0.000) between groups. The cutoff points that revealed the highest specificity for the AVQI, ABI, and DSI respectively were 3.33 (sensitivity 57.1% and specificity 90.5%), 4 (sensitivity 57.1% and specificity 85.7%), and 1.62 (sensitivity 71.4% and specificity 90.5%).

CONCLUSION

The AVQI, ABI, and DSI are instruments that provide robust voice information and can help speech-language pathologists in their decision-making about whether teachers must or must not be restricted in their vocal activities at work.

Wind farm noise shifts vocalizations of a threatened shrub-steppe passerine

Wind energy has experienced a notable development during the last decades, driving new challenges for animal communities. Although bird collisions with wind turbines and spatial displacement due to disturbance have been widely described in the literature, other potential impacts remain unclear. In this study, we addressed the effect of turbine noise on the vocal behaviour of a threatened shrub-steppe passerine highly dependent on acoustic communication, the Dupont's lark Chersophilus duponti. Based on directional recordings of 49 calling and singing males exposed to a gradient of turbine noise level (from 15 up to 51 dBA), we tested for differences in signal diversity, redundancy, and complexity, as well as temporal and spectral characteristics of their vocalizations (particularly the characteristic whistle). Our results unveiled that Dupont's lark males varied the vocal structure when subject to turbine noise, by increasing the probability of emitting more complex whistles (with increased number of notes) and shifting the dominant note (emphasizing the longest and higher-pitched note). In addition, males increased duration and minimum frequency of specific notes of the whistle, while repertoire size and signal redundancy remain constant. To our knowledge, this is the first study reporting multiple and complex responses on the vocal repertoire of animals exposed to turbine noise and unveiling a shift of the dominant note in response to anthropogenic noise in general. These findings suggest that the Dupont's lark exhibits some level of phenotypic plasticity, which might enable the species to cope with noisy environments, although the vocal adjustments observed might have associated costs or alter the functionality of the signal. Future wind energy projects must include fine-scale noise assessments to quantify the consequences of chronic noise exposure.

Are Acoustic Markers of Voice and Speech Signals Affected by Nose-and-Mouth-Covering Respiratory Protective Masks?

Background

Worldwide use of nose-and-mouth-covering respiratory protective mask (RPM) has become ubiquitous during COVID19 pandemic. Consequences of wearing RPMs, especially regarding perception and production of spoken communication, are gradually emerging. The present study explored how three prevalent RPMs affect various speech and voice sound properties.

Methods

Pre-recorded sustained [a] vowels and read sentences from 47 subjects were played by a speech production model (‘Voice Emitted by Spare Parts’, or ‘VESPA’) in four conditions: without RPM (C1), with disposable surgical mask (C2), with FFP2 mask (C3), and with transparent plastic mask (C4). Differences between C1 and masked conditions were assessed with Dunnett's t test in 26 speech sound properties related to voice production (fundamental frequency, sound intensity level), voice quality (jitter percent, shimmer percent, harmonics-to-noise ratio, smoothed cepstral peak prominence, Acoustic Voice Quality Index), articulation and resonance (first and second formant frequencies, first and second formant bandwidths, spectral center of gravity, spectral standard deviation, spectral skewness, spectral kurtosis, spectral slope, and spectral energy in ten 1-kHz bands from 0 to 10 kHz).

Results

C2, C3, and C4 significantly affected 10, 15, and 19 of the acoustic speech markers, respectively. Furthermore, absolute differences between unmasked and masked conditions were largest for C4 and smallest for C2.

Conclusions

All RPMs influenced more or less speech sound properties. However, this influence was least for surgical RPMs and most for plastic RPMs. Surgical RPMs are therefore preferred when spoken communication is priority next to respiratory protection.

Vocal Quality After a Performance in Actors Compared to Dancers

STATE OF THE ART

Theater actors are a high risk group for developing voice disorders.

AIMS

The first purpose of this study was to examine and compare the objective and subjective vocal quality between professional theater actors, non-professional theater actors and a control group of professional dancers. Secondly, the impact of one theater performance on the objective and subjective vocal quality was investigated within and between the groups. It is hypothesized that actors will experience vocal fatigue and a deteriorated vocal quality compared with dancers as a result of the vocal load during the performance. Dancers will face more general fatigue and smaller vocal changes due to the impact of a performance including stress, decompensation and physical fatigue.

METHODS

Recordings of 27 professional actors, 19 non-professional actors and 16 professional dancers were collected before and after a performance using the PRAAT software. Voice samples included sustained vowel phonation, continuous speech, aerodynamic measurements and voice range profile. Both Acoustic Voice Quality Index and Dysphonia Severity Index were computed. For auditory-perceptual evaluations the GRBASI scale was used. Several questionnaires were completed pre and post performance to capture vocal risk factors.

RESULTS

Vocal quality between groups showed lower fundamental frequency (f_o) values (female), larger fundamental frequency (female) and intensity ranges and a longer maximum phonation time (female) in professional actors compared to non-professionals. Professional dancers showed higher Acoustic Voice Quality Index values compared to non-professional actors. Dysphonia Severity Index, Voice Handicap Index, Vocal Tract Discomfort Scale and GRBASI results did not differ between groups at the baseline. Both objective measurements and questionnaires did not show significantly different results post performance. Questionnaires revealed poor vocal habits in professional actors.

CONCLUSION

Professional actors have better vocal capacities than non-professionals. Dancers' vocal quality is worse than actors. The results show no impact of one performance on the vocal quality in theater actors and dancers. The long-term impact of performing, however, is subject for further research.

Recommended Protocols for Instrumental Assessment of Voice: American Speech-Language-Hearing Association Expert Panel to Develop a Protocol for Instrumental Assessment of Vocal Function

PURPOSE

The aim of this study was to recommend protocols for instrumental assessment of voice production in the areas of laryngeal endoscopic imaging, acoustic analyses, and aerodynamic procedures, which will (a) improve the evidence for voice assessment measures, (b) enable valid comparisons of assessment results within and across clients and facilities, and (c) facilitate the evaluation of treatment efficacy.

METHOD

Existing evidence was combined with expert consensus in areas with a lack of evidence. In addition, a survey of clinicians and a peer review of an initial version of the protocol via VoiceServe and the American Speech-Language-Hearing Association's Special Interest Group 3 (Voice and Voice Disorders) Community were used to create the recommendations for the final protocols.

RESULTS

The protocols include recommendations regarding technical specifications for data acquisition, voice and speech tasks, analysis methods, and reporting of results for instrumental evaluation of voice production in the areas of laryngeal endoscopic imaging, acoustics, and aerodynamics.

CONCLUSION

The recommended protocols for instrumental assessment of voice using laryngeal endoscopic imaging, acoustic, and aerodynamic methods will enable clinicians and researchers to collect a uniform set of valid and reliable measures that can be compared across assessments, clients, and facilities.

Tutorial and Guidelines on Measurement of Sound Pressure Level in Voice and Speech

PURPOSE

Sound pressure level (SPL) measurement of voice and speech is often considered a trivial matter, but the measured levels are often reported incorrectly or incompletely, making them difficult to compare among various studies. This article aims at explaining the fundamental principles behind these measurements and providing guidelines to improve their accuracy and reproducibility.

METHOD

Basic information is put together from standards, technical, voice and speech literature, and practical experience of the authors and is explained for nontechnical readers.

RESULTS

Variation of SPL with distance, sound level meters and their accuracy, frequency and time weightings, and background noise topics are reviewed. Several calibration procedures for SPL measurements are described for stand-mounted and head-mounted microphones.

CONCLUSIONS

SPL of voice and speech should be reported together with the mouth-to-microphone distance so that the levels can be related to vocal power. Sound level measurement settings (i.e., frequency weighting and time weighting/averaging) should always be specified. Classified sound level meters should be used to assure measurement accuracy. Head-mounted microphones placed at the proximity of the mouth improve signal-to-noise ratio and can be taken advantage of for voice SPL measurements when calibrated. Background noise levels should be reported besides the sound levels of voice and speech.