Mobile Communication Devices, Ambient Noise, and Acoustic Voice Measures

Female African elephant rumbles differ between populations and sympatric social groups

Vocalizations often vary in structure within a species, from the individual to population level. Vocal differences among social groups and populations can provide insight into biological processes such as vocal learning and evolutionary divergence, with important conservation implications. As vocal learners of conservation concern, intraspecific vocal variation is of particular interest in elephants. We recorded calls from individuals in multiple, wild elephant social groups in two distinct Kenyan populations. We used machine learning to investigate vocal differentiation among individual callers, core groups, bond groups (collections of core groups) and populations. We found clear evidence for vocal distinctiveness at the individual and population level, and evidence for much subtler vocal differences among social groups. Social group membership was a better predictor of call similarity than genetic relatedness, suggesting that subtle vocal differences among social groups may be learned. Vocal divergence among populations and social groups has conservation implications for the effects of social disruption and translocation of elephants.

Validity of Acoustic Measures Obtained Using Various Recording Methods Including Smartphones With and Without Headset Microphones

PURPOSE

The goal of this study was to assess various recording methods, including combinations of high- versus low-cost microphones, recording interfaces, and smartphones in terms of their ability to produce commonly used time- and spectral-based voice measurements.

METHOD

Twenty-four vowel samples representing a diversity of voice quality deviations and severities from a wide age range of male and female speakers were played via a head-and-thorax model and recorded using a high-cost, research standard GRAS 40AF (GRAS Sound & Vibration) microphone and amplification system. Additional recordings were made using various combinations of headset microphones (AKG C555 L [AKG Acoustics GmbH], Shure SM35-XLR [Shure Incorporated], AVID AE-36 [AVID Products, Inc.]) and audio interfaces (Focusrite Scarlett 2i2 [Focusrite Audio Engineering Ltd.] and PC, Focusrite and smartphone, smartphone via a TRRS adapter), as well as smartphones direct (Apple iPhone 13 Pro, Google Pixel 6) using their built-in microphones. The effect of background noise from four different room conditions was also evaluated. Vowel samples were analyzed for measures of fundamental frequency, perturbation, cepstral peak prominence, and spectral tilt (low vs. high spectral ratio).

RESULTS

Results show that a wide variety of recording methods, including smartphones with and without a low-cost headset microphone, can effectively track the wide range of acoustic characteristics in a diverse set of typical and disordered voice samples. Although significant differences in acoustic measures of voice may be observed, the presence of extremely strong correlations (rs > .90) with the recording standard implies a strong linear relationship between the results of different methods that may be used to predict and adjust any observed differences in measurement results.

CONCLUSION

Because handheld smartphone distance and positioning may be highly variable when used in actual clinical recording situations, smartphone + a low-cost headset microphone is recommended as an affordable recording method that controls mouth-to-microphone distance and positioning and allows both hands to be available for manipulation of the smartphone device.

Clinical classification of memory and cognitive impairment with multimodal digital biomarkers

INTRODUCTION

Early detection of Alzheimer's disease and cognitive impairment is critical to improving the healthcare trajectories of aging adults, enabling early intervention and potential prevention of decline.

METHODS

To evaluate multi-modal feature sets for assessing memory and cognitive impairment, feature selection and subsequent logistic regressions were used to identify the most salient features in classifying Rey Auditory Verbal Learning Test-determined memory impairment.

RESULTS

Multimodal models incorporating graphomotor, memory, and speech and voice features provided the stronger classification performance (area under the curve = 0.83; sensitivity = 0.81, specificity = 0.80). Multimodal models were superior to all other single modality and demographics models.

DISCUSSION

The current research contributes to the prevailing multimodal profile of those with cognitive impairment, suggesting that it is associated with slower speech with a particular effect on the duration, frequency, and percentage of pauses compared to normal healthy speech.

Multiparametric Analysis of Speaking Fundamental Frequency in Genetically Related Speakers Using Different Speech Materials: Some Forensic Implications

OBJECTIVES

To assess the speaker-discriminatory potential of a set of fundamental frequency estimates in intraidentical twin pair comparisons and cross-pair comparisons (i.e., among all speakers).

PARTICIPANTS

A total of 20 Brazilian Portuguese speakers of the same dialect, namely 10 male identical twin pairs aged between 19 and 35, were recruited.

METHOD

The participants were recorded directly through professional microphones while taking part in a spontaneous dialogue over mobile phones. Acoustic measurements were performed in connected speech samples, and in lengthened vowels, at least 160 ms long produced during spontaneous speech.

RESULTS

f0 baseline, central tendency, and extreme values were found mostly discriminatory in intra-twin pair and cross-pair comparisons. These were also the estimates displaying the largest effect sizes. Overall, only three identical twins were found statistically different regarding their f0 patterns in connected speech, but not for lengthened vowel-based f0 metrics. Estimates of f0 variation and modulation were found the least discriminatory across speakers, which may signal the control of speaking style and dialect on dynamic patterns of f0. Concerning system performance, the base value of f0 (f0 baseline) was found the most reliable metric, displaying the lowest equal error rate (EER).

CONCLUSIONS

The outcomes suggest that, although identical twins were very closely related regarding their f0 patterns, some pairs could still be differentiated acoustically, only in connected speech. Such findings reinforce the relevance of analyzing long-term f0 metrics for speaker comparison purposes, with particular consideration to f0 baseline. Furthermore, f0 differences across subjects were suggested as more expressive in connected speech than in lengthened vowels.

The Efficacy of the Manual Circumlaryngeal Therapy for Muscle Tension Dysphonia: A Systematic Review and Meta-analysis

OBJECTIVE

Muscle tension dysphonia (MTD) is the most common functional voice disorder. Behavioral voice therapy is the front-line treatment for MTD, and laryngeal manual therapy may be a part of this treatment. The objective of this study was to investigate the effect of manual circumlaryngeal therapy (MCT) on acoustic markers of voice quality (jitter, shimmer, and harmonics-to-noise ratio) and vocal function (fundamental frequency) through a systematic review with meta-analysis.

DATA SOURCES

Four databases were searched from inception to December 2022, and a manual search was performed.

REVIEW METHODS

The PRISMA extension statement for reporting systematic reviews incorporating a meta-analysis of health care interventions was applied, and a random effects model was used for the meta-analyses.

RESULTS

We identified 6 eligible studies from 30 studies (without duplicates). The MCT approach was highly effective on acoustics with large effect sizes (Cohen's d > 0.8). Significant improvements were obtained in jitter in percent (mean difference of -.58; 95% CI -1.00 to 0.16), shimmer in percent (mean difference of -5.66; 95% CI -8.16 to 3.17), and harmonics-to-noise ratio in dB (mean difference of 4.65; 95% CI 1.90-7.41), with the latter two measurements continuing to be significantly improved by MCT when measurement variability is considered.

CONCLUSION

The efficacy of MCT for MTD was confirmed in most clinical studies by assessing jitter, shimmer, and harmonics-to-noise ratio related to voice quality. The effects of MCT on the fundamental frequency changes could not be verified. Further contributions of high-quality randomized control trials are needed to support evidence-based practice in laryngology. Laryngoscope, 134:18-26, 2024.

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.

Utility of Smart Phones as a Voice Acquisition Device for Assessing Pre and Post Treatment Voice Using PRAAT

Voice assessment before and after treatment helps the clinician to assess the effectiveness of the treatment given and facilitates comparison between different treatment modalities. Voice handicap index -10(VHI-10) questionnaire is a tool which allows the voice to be evaluated subjectively from the patient's perspective. PRAAT is a freely available, software programme that acoustically analyse voice signals. Smart phones are widely used and the high quality of the embedded microphone in it makes it a suitable and easily available voice recording device. This study aims at using PRAAT and VHI-10 questionnaire in evaluating voice before and after treatment. The utility of smart phones as a voice acquisition device is also explored in the study. Prospective, observational study, carried out from 1st November 2019 to 30th September 2021in the ENT out- patient department at a tertiary hospital in Punjab. 58 patients complaining of dysphonia were enrolled consecutively in the study. All patients underwent detailed history, examination of the larynx using 70-degree rigid laryngoscope. The voice handicap was scored by (VHI-10) questionnaire and acoustic evaluation of voice was done using the PRAAT software. Patients' voice was further evaluated 3 months post-therapy with VHI 10 questionnaire and acoustic analysis. The parameters measured on PRAAT were mean pitch, jitter (local), shimmer (local), and mean harmonics to noise ratio (HNR). The voice was recorded using a smart phone and later transferred onto a laptop for analysis. The pre and post treatment acoustic parameters and VHI-10 scores were compared and correlated. There was significant difference (p < 0.001) between the pre and post treatment VHI-10 scores and all the acoustic parameters measured except for median pitch (p = 0.995). A poor positive correlation was found between the pre treatment VHI-10 scores and jitter(r = 0.188, p = 0.157) and shimmer (r = 0.288, p = 0.028) values. A negative correlation was observed between pre treatment VHI-10 scores and pitch (r = - 0.151, p = 0.259) and HNR(r = - 0.424, p = 0.001). Post treatment VHI-10 scores showed positive correlation with jitter (r = 0.302, p = 0.021) and shimmer (0.162, p = 0.225) values and negative correlation with pitch (r = - 0.10, p = 0.457) and HNR (r = - 0.356, p = 0.006) values. We found significant differences in the VHI-10 scores and PRAAT voice analysis results before and after treatment in patients complaining with voice change (dysphonia). VHI-10 questionnaire and PRAAT are good and convenient tools for assessing the voice subjectively and objectively. Only a poor to fair correlation was found between VHI-10 scores and PRAAT analysis results. More studies must be done to confirm the utility of smart phones as a voice acquisition device and PRAAT software in voice analysis.

Smartphone-Based Voice Wellness Index Application for Dysphonia Screening and Assessment: Development and Reliability

OBJECTIVE

This study aimed to develop a Voice Wellness Index (VWI) application combining the acoustic voice quality index (AVQI) and glottal function index (GFI) data and to evaluate its reliability in quantitative voice assessment and normal versus pathological voice differentiation.

STUDY DESIGN

Cross-sectional study.

METHODS

A total of 135 adult participants (86 patients with voice disorders and 49 patients with normal voices) were included in this study. Five iOS and Android smartphones with the "Voice Wellness Index" app installed were used to estimate VWI. The VWI data obtained using smartphones were compared with VWI measurements computed from voice recordings collected from a reference studio microphone. The diagnostic efficacy of VWI in differentiating between normal and disordered voices was assessed using receiver operating characteristics (ROC).

RESULTS

With a Cronbach's alpha of 0.972 and an ICC of 0.972 (0.964-0.979), the VWI scores of the individual smartphones demonstrated remarkable inter-smartphone agreement and reliability. The VWI data obtained from different smartphones and a studio microphone showed nearly perfect direct linear correlations (r = 0.993-0.998). Depending on the individual smartphone device used, the cutoff scores of VWI related to differentiating between normal and pathological voice groups were calculated as 5.6-6.0 with the best balance between sensitivity (94.10-95.15%) and specificity (93.68-95.72%), The diagnostic accuracy was excellent in all cases, with an area under the curve (AUC) of 0.970-0.974.

CONCLUSION

The "Voice Wellness Index" application is an accurate and reliable tool for voice quality measurement and normal versus pathological voice screening and has considerable potential to be used by healthcare professionals and patients for voice assessment.

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.

Reliability of Universal-Platform-Based Voice Screen Application in AVQI Measurements Captured with Different Smartphones

The aim of the study was to develop a universal-platform-based (UPB) application suitable for different smartphones for estimation of the Acoustic Voice Quality Index (AVQI) and evaluate its reliability in AVQI measurements and normal and pathological voice differentiation. Our study group consisted of 135 adult individuals, including 49 with normal voices and 86 patients with pathological voices. The developed UPB "Voice Screen" application installed on five iOS and Android smartphones was used for AVQI estimation. The AVQI measures calculated from voice recordings obtained from a reference studio microphone were compared with AVQI results obtained using smartphones. The diagnostic accuracy of differentiating normal and pathological voices was evaluated by applying receiver-operating characteristics. One-way ANOVA analysis did not detect statistically significant differences between mean AVQI scores revealed using a studio microphone and different smartphones (F = 0.759; p = 0.58). Almost perfect direct linear correlations (r = 0.991-0.987) were observed between the AVQI results obtained with a studio microphone and different smartphones. An acceptable level of precision of the AVQI in discriminating between normal and pathological voices was yielded, with areas under the curve (AUC) displaying 0.834-0.862. There were no statistically significant differences between the AUCs (p > 0.05) obtained from studio and smartphones' microphones. The significant difference revealed between the AUCs was only 0.028. The UPB "Voice Screen" application represented an accurate and robust tool for voice quality measurements and normal vs. pathological voice screening purposes, demonstrating the potential to be used by patients and clinicians for voice assessment, employing both iOS and Android smartphones.

Smartphone Recordings are Comparable to "Gold Standard" Recordings for Acoustic Measurements of Voice

PURPOSE

The purpose of this study was to assess the relationship and comparability of cepstral and spectral measures of voice obtained from a high-cost "flat" microphone and precision sound level meter (SLM) vs. high-end and entry level models of commonly and currently used smartphones (iPhone i12 and iSE; Samsung s21 and s9 smartphones). Device comparisons were also conducted in different settings (sound-treated booth vs. typical "quiet" office room) and at different mouth-to-microphone distances (15 and 30 cm).

METHODS

The SLM and smartphone devices were used to record a series of speech and vowel samples from a prerecorded diverse set of 24 speakers representing a wide range of sex, age, fundamental frequency (F0), and voice quality types. Recordings were analyzed for the following measures: smoothed cepstral peak prominence (CPP in dB); the low vs high spectral ratio (L/H Ratio in dB); and the Cepstral Spectral Index of Dysphonia (CSID).

RESULTS

A strong device effect was observed for L/H Ratio (dB) in both vowel and sentence contexts and for CSID in the sentence context. In contrast, device had a weak effect on CPP (dB), regardless of context. Recording distance was observed to have a small-to-moderate effect on measures of CPP and CSID but had a negligible effect on L/H Ratio. With the exception of L/H Ratio in the vowel context, setting was observed to have a strong effect on all three measures. While these aforementioned effects resulted in significant differences between measures obtained with SLM vs. smartphone devices, the intercorrelations of the measurements were extremely strong (r's > 0.90), indicating that all devices were able to capture the range of voice characteristics represented in the voice sample corpus. Regression modeling showed that acoustic measurements obtained from smartphone recordings could be successfully converted to comparable measurements obtained by a "gold standard" (precision SLM recordings conducted in a sound-treated booth at 15 cm) with small degrees of error.

CONCLUSIONS

These findings indicate that a variety of commonly available modern smartphones can be used to collect high quality voice recordings usable for informative acoustic analysis. While device, setting, and distance can have significant effects on acoustic measurements, these effects are predictable and can be accounted for using regression modeling.

Microphone and Audio Compression Effects on Acoustic Voice Analysis: A Pilot Study

OBJECTIVE

This study aimed to analyze the effects of microphone and audio compression variables on voice and speech parameters acquisition.

METHOD

Acoustic measures were recorded and compared using a high-quality reference microphone and three testing microphones. The tested microphones displayed differences in specifications and acoustic properties. Furthermore, the impact of the audio compression was assessed by resampling the original uncompressed audio files into the MPEG-1/2 Audio Layer 3 (mp3) format at three different compression rates (128 kbps, 64 kbps, 32 kbps). Eight speakers were recruited in each recording session and asked to produce four sustained vowels: two [a] segments and two [ɛ] segments. The audio was captured simultaneously by the reference and tested microphones. The recordings were synchronized and analyzed using the Praat software.

RESULTS

From a set of eight acoustic parameters assessed (f₀, F1, F2, jitter%, shimmer%, HNR, H1-H2, and CPP), three (f₀, F2, and jitter%) were suggested as resistant regarding the microphone and audio compression variables. In contrast, some parameters seemed to be significantly affected by both factors: HNR, H1-H2, and CPP; while shimmer% was found sensitive only concerning the latter factor. Moreover, higher compression rates appeared to yield more frequent acoustic distortions than lower rates.

CONCLUSION

Overall, the outcomes suggest that acoustic parameters are influenced by both the microphone selection and the audio compression usage, which may reflect the practical implications of these components on the acoustic analysis reliability.

Comparison of In-Person and Online Recordings in the Clinical Teleassessment of Speech Production: A Pilot Study

In certain circumstances, speech and language therapy is proposed in telepractice as a practical alternative to in-person services. However, little is known about the minimum quality requirements of recordings in the teleassessment of motor speech disorders (MSD) utilizing validated tools. The aim here is to examine the comparability of offline analyses based on speech samples acquired from three sources: (1) in-person recordings with high quality material, serving as the baseline/gold standard; (2) in-person recordings with standard equipment; (3) online recordings from videoconferencing. Speech samples were recorded simultaneously from these three sources in fifteen neurotypical speakers performing a screening battery of MSD and analyzed by three speech and language therapists. Intersource and interrater agreements were estimated with intraclass correlation coefficients on seventeen perceptual and acoustic parameters. While the interrater agreement was excellent for most speech parameters, especially on high quality in-person recordings, it decreased in online recordings. The intersource agreement was excellent for speech rate and mean fundamental frequency measures when comparing high quality in-person recordings to the other conditions. The intersource agreement was poor for voice parameters, but also for perceptual measures of intelligibility and articulation. Clinicians who plan to teleassess MSD should adapt their recording setting to the parameters they want to reliably interpret.

An iOS-based VoiceScreen application: feasibility for use in clinical settings-a pilot study

OBJECTIVES

To elaborate the application suitable for smartphones for estimation of Acoustic Voice Quality Index (AVQI) and evaluate its usability in the clinical setting.

METHODS

An elaborated AVQI automatization and background noise monitoring functions were implemented into a mobile "VoiceScreen" application running the iOS operating system. A study group consisted of 103 adult individuals with normal voices (n = 30) and 73 patients with pathological voices. Voice recordings were performed in the clinical setting with "VoiceScreen" app using iPhone 8 microphones. Voices of 30 patients were recorded before and 1 month after phonosurgical intervention. To evaluate the diagnostic accuracy differentiating normal and pathological voice, the receiver-operating characteristic statistics, i.e., area under the curve (AUC), sensitivity and specificity, and correct classification rate (CCR) were used.

RESULTS

A high level of precision of AVQI in discriminating between normal and dysphonic voices was yielded with corresponding AUC = 0.937. The AVQI cutoff score of 3.4 demonstrated a sensitivity of 86.3% and specificity of 95.6% with a CCR of 89.2%. The preoperative mean value of the AVQI [6.01(SD 2.39)] in the post-phonosurgical follow-up group decreased to 2.00 (SD 1.08). No statistically significant differences (p = 0.216) between AVQI measurements in a normal voice and 1-month follow-up after phonosurgery groups were revealed.

CONCLUSIONS

The "VoiceScreen" app represents an accurate and robust tool for voice quality measurement and demonstrates the potential to be used in clinical settings as a sensitive measure of voice changes across phonosurgical treatment outcomes.

Comparison of Acoustic Voice Features Derived From Mobile Devices and Studio Microphone Recordings

OBJECTIVES/HYPOTHESIS

Improvements in mobile device technology offer new opportunities for remote monitoring of voice for home and clinical assessment. However, there is a need to establish equivalence between features derived from signals recorded from mobile devices and gold standard microphone-preamplifiers. In this study acoustic voice features from android smartphone, tablet, and microphone-preamplifier recordings were compared.

METHODS

Data were recorded from 37 volunteers (20 female) with no history of speech disorder and six volunteers with Huntington's disease (HD) during sustained vowel (SV) phonation, reading passage (RP), and five syllable repetition (SR) tasks. The following features were estimated: fundamental frequency median and standard deviation (F0 and SD F0), harmonics-to-noise ratio (HNR), local jitter, relative average perturbation of jitter (RAP), five-point period perturbation quotient (PPQ5), difference of differences of amplitude and periods (DDA and DDP), shimmer, and amplitude perturbation quotients (APQ3, APQ5, and APQ11).

RESULTS

Bland-Altman analysis revealed good agreement between microphone and mobile devices for fundamental frequency, jitter, RAP, PPQ5, and DDP during all tasks and a bias for HNR, shimmer and its variants (APQ3, APQ5, APQ11, and DDA). Significant differences were observed between devices for HNR, shimmer, and its variants for all tasks. High correlation was observed between devices for all features, except SD F0 for RP. Similar results were observed in the HD group for SV and SR task. Biological sex had a significant effect on F0 and HNR during all tests, and for jitter, RAP, PPQ5, DDP, and shimmer for RP and SR. No significant effect of age was observed.

CONCLUSIONS

Mobile devices provided good agreement with state of the art, high-quality microphones during structured speech tasks for features derived from frequency components of the audio recordings. Caution should be taken when estimating HNR, shimmer and its variants from recordings made with mobile devices.

Mobile Phone Applications Voice Tools and Voice Pitch Analyzer Validated With LingWAVES to Measure Voice Frequency

OBJECTIVES

Voice frequency can be measured to assess the voice change in transgender men and women during treatment. There are many applications that can analyze voice frequency. This validation study aimed to compare the ability to measure voice frequency of the mobile phone applications "Voice Tools" and "Voice Pitch Analyzer" with the registration program LingWAVES as the gold standard.

STUDY DESIGN

Prospective validation study.

METHODS

A total of 45 participants of whom 20 transgender individuals were included. They were asked to read "The North Wind and the Sun" twice. The first measurement compared voice frequency measured by Voice Tools with LingWAVES while the second measurement compared Voice Pitch Analyzer with LingWAVES. The two applications that were being compared simultaneously measured the voice frequency. Pearson's regression correlations were performed to test for correlation between the mobile phone applications and LingWAVES.

RESULTS

Significant correlations were demonstrated between the measurements of Voice Tools and LingWAVES (P < 0.001) and between Voice Pitch Analyzer and LingWAVES (P < 0.001). Voice Tools overestimated voice frequency with a median deviation of 2Hz (range -4 to 20). The overestimation was more pronounced in the high ranges. Voice Pitch Analyzer showed underestimation of voice frequency in high ranges. Median deviation was -2Hz (range -16 to 14).

CONCLUSIONS

This validation study shows that voice frequency can be reliably measured with the mobile phone applications "Voice Tools" and "Voice Pitch Analyzer". Combined with the ease of use, these applications can be used to measure voice frequency in clinical practice and for research purposes.

Voice Therapy for Older Adults During the COVID-19 Pandemic in Brazil

OBJECTIVE

To characterize the clinical practice of Brazilian speech-language-hearing therapists regarding voice therapy for older adults during the COVID-19 pandemic.

METHODS

Cross-sectional survey conducted remotely. Data were collected through a form shared online with approximately 1.500 speech-language-hearing therapists. The form included voice therapy practice with older adults during the COVID-19 pandemic. It was responded by 155 voice experts.

RESULTS

Most respondents were females with over 21 years' experience in vocal health care, working with both in-person therapy and teletherapy. Obtaining acoustic parameters and using therapy strategies for breathing and body training were the most reported changes in remote therapy during the pandemic. The main difficulties involved wearing masks in in-person therapy and assessing the voice in teletherapy. Patient adherence and goals reached were deemed positive by most participants. Associations were found between place and format of service; between patient adherence and goals reached; and between difficulties in teletherapy and use of complementary therapeutic resources.

CONCLUSION

The COVID-19 pandemic led Brazilian speech-language-hearing therapists to change their clinical practice with older adults in both remote and in-person therapy. The main changes involved wearing masks in in-person therapy and assessing the voice in teletherapy. Remote therapy proved to be a safe and effective possibility.

Voice Quality in Telephone Interviews: A preliminary Acoustic Investigation

OBJECTIVES

To investigate the impact of standardized mobile phone recordings passed through a telecom channel on acoustic markers of voice quality and on its perception by voice experts in normophonic speakers.

METHODS

Continuous speech and a sustained vowel were recorded for fourteen female and ten male normophonic speakers. The recordings were done simultaneously with a head-mounted high-quality microphone and through the telephone network on a receiving smartphone. Twenty-two acoustic voice quality, breathiness and pitch-related measures were extracted from the recordings. Nine vocologists perceptually rated the G, R and B parameters of the GRBAS scale on each voice sample. The reproducibility, the recording type, the stimulus type and the gender effects, as well as the correlation between acoustic and perceptual measures were investigated.

RESULTS

The sustained vowel samples are damped after one second. Only the frequencies between 100 and 3700Hz are passed through the telecom channel and the frequency response is characterized by peaks and troughs. The acoustic measures show a good reproducibility over the three repetitions. All measures significantly differ between the recording types, except for the local jitter, the harmonics-to-noise ratio by Dejonckere and Lebacq, the period standard deviation and all six pitch measures. The AVQI score is higher in telephone recordings, while the ABI score is lower. Significant differences between genders are also found for most of the measures; while the AVQI is similar in men and women, the ABI is higher in women in both recording types. For the perceptual assessment, the interrater agreement is rather low, while the reproducibility over the three repetitions is good. Few significant differences between recording types are observed, except for lower breathiness ratings on telephone recordings. G ratings are significantly more severe on the sustained vowel on both recording types, R ratings only on telephone recordings. While roughness is rated higher in men on telephone recordings by most experts, no gender effect is observed for breathiness on either recording types. Finally, neither the AVQI nor the ABI yield strong correlations with any of the perceptual parameters.

CONCLUSIONS

Our results show that passing a voice signal through a telecom channel induces filter and noise effects that limit the use of common acoustic voice quality measures and indexes. The AVQI and ABI are both significantly impacted by the recording type. The most reliable acoustic measures seem to be pitch perturbation (local jitter and period standard deviation) as well as the harmonics-to-noise ratio from Dejonckere and Lebacq. Our results also underline that raters are not equally sensitive to the various factors, including the recording type, the stimulus type and the gender effects. Neither of the three perceptual parameters G, R and B seem to be reliably measurable on telephone recordings using the two investigated acoustic indexes. Future studies investigating the impact of voice quality in telephone conversations should thus focus on acoustic measures on continuous speech samples that are limited to the frequency response of the telecom channel and that are not too sensitive to environmental and additive noise.

Meta-Analysis on the Validity of the Acoustic Voice Quality Index

BACKGROUND

Acoustic measurements are useful tools to objectively measure overall voice quality. The Acoustic Voice Quality Index (AVQI) has shown to be a valid multiparametric tool to objectify dysphonia severity. The increasing number of validity studies investigating AVQI's validity demands a comprehensive synthesis of the available outcomes.

OBJECTIVE OF REVIEW

The aim of the present meta-analysis is to quantify the evidence for the diagnostic accuracy of the AVQI, including its sensitivity, specificity and likelihood ratio statistics, and its concurrent validity and sensitivity to changes in auditory-perceptual voice quality ratings.

TYPE OF REVIEW

Meta-analysis SEARCH STRATEGY: MEDLINE, EMBASE, the Cochrane library and Web of Science were searched from 2010 till April 2021 with an additional manual search, using keywords related to AVQI and common terminologies of validity outcomes. Studies considering the clinical validity of AVQI (ie, diagnostic accuracy, concurrent validity and sensitivity to change), using auditory-perceptual voice quality evaluation as reference, were included.

EVALUATION METHOD

The Preferred Reporting Items for Systematic reviews and Meta-Analyses of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines were used. Quality assessment of included studies was conducted using the QUADAS-2 tool. For the diagnostic accuracy of AVQI, the pooled sensitivity, specificity and likelihood ratio statistics were determined using a summary receiver operating characteristic approach. Weighted correlation coefficient measures (rW¯) were used to assess the concurrent validity and sensitivity to change.

RESULTS

A total of 198 studies were screened and 33 articles were included. In total, voice samples of 11447, 10272, and 367 different subjects were considered for analysis of diagnostic accuracy, concurrent validity and change responsiveness, respectively. Satisfying diagnostic accuracy results were found with a pooled sensitivity of 0.83 (95% CI: 0.82-0.83), a pooled specificity of 0.89 (95% CI: 0.88-0.90), a pooled positive LR of 7.75 (95% CI: 6.04-9.95), a pooled negative LR of 0.20 (95% CI: 0.16-0.23), and a pooled diagnostic odds ratio of 47.13 (95% CI: 34.82-63.79). Summary receiver operating characteristic curve analysis showed an excellent AUC value of 0.937 and Q* index of 0.874. Strong correlations of rW¯ = 0.838 for concurrent validity and rW¯ = 0.796 for sensitivity to change were found.

CONCLUSIONS

Our results confirm the general clinical utility of the AVQI as a robust and valid objective measure for evaluating overall dysphonia severity across languages and study methods.

Comparison of Client-Led Asynchronous and Clinician-Led Synchronous Online Methods for Evaluation of Subjective Vocal Measures in Teachers: A Feasibility Study

BACKGROUND

COVID-19 has transformed face to face teaching in classrooms to online and hybrid modes. Increased vocal intensity/ pitch to call attention of students and transact in the online class, inappropriate posture (head, neck & upper trunk) while using the laptop and other online tools cause vocal loading leading to voice related concerns in teachers. Tele voice assessment is a feasible alternative means to seek professional help in the current situation and possibly in the future too. Client-led asynchronous and clinician-led synchronous voice recordings for clinical vocal measures among school teachers were compared in this study.

METHOD

Twenty-five school teachers (21 females & four males) from Chennai consented to the study. Information of voice use, its impact on the day-to-day situations, self-perception of vocal fatigue, and their recorded voice sample (phonation & speaking) were obtained online (asynchronous mode). Within a period of ten days, the clinician-led synchronous session was planned on a mutually convenient time for obtaining voice samples through zoom call. The voice samples obtained were compared for clinical measures and perceptual voice evaluation.

RESULTS

Participants reported of vocal symptoms and increased vocal fatigue scores. The maximum phonation time values obtained through synchronous mode were lesser when compared to asynchronous mode. Also, variability was noted in the perceptual vocal measures of voice samples obtained through synchronous mode. During synchronous voice recording & evaluation, the background noise, internet stability, audio enhancement feature, and microphone placement & quality could be monitored, and immediate feedback was provided. Additionally, the asynchronous recording can be supplemented for synchronous recording, with clear instructions & demonstration.

CONCLUSION

This study explored the feasibility of using synchronous and asynchronous voice recording for voice analysis in school teachers. The findings could serve as a base to understand the advantages and challenges of using client-led asynchronous and clinician-led synchronous methods for estimating vocal measures.

Uso del smartphone en telepráctica para trastornos de la voz. Una revisión desde el concepto de Mhealth

El uso de los smartphones y el concepto de mobile health (mHealth) es reciente en vocología y sus posibles beneficios en el tratamiento y entrenamiento vocal en contexto de telepráctica. Se realizó una revisión narrativa con el objetivo describir los beneficios de la mHealth a través del smartphone en el contexto de la telepráctica fonoaudiológica de los trastornos vocales. Se buscaron artículos científicos en Pubmed, ScienceDirect y Google Scholar, asociados al uso del smartphone en vocología, considerando voces humanas normales, patológicas y voces sintéticas; relacionados a la intervención, evaluación, valoración, monitoreo, prevención, intervención, supervisión, educación, consulta y entrenamiento vocal. Se revisaron 42 estudios, de los cuales fueron seleccionados 15 de acuerdo a los criterios de inclusión. Los estudios analizados se relacionan con grabación de voz para análisis acústico con smartphone, teleterapia con smartphone y dispositivos periféricos para análisis vocal y seguimiento. Se destaca el potencial de los dispositivos móviles para incrementar accecibilidad, reducir costos y favorecer el seguimiento terapéutico con medidas objetivas en diversos contextos de salud vocal.

An Analytical Study of Speech Pathology Detection Based on MFCC and Deep Neural Networks

Diseases of internal organs other than the vocal folds can also affect a person's voice. As a result, voice problems are on the rise, even though they are frequently overlooked. According to a recent study, voice pathology detection systems can successfully help the assessment of voice abnormalities and enable the early diagnosis of voice pathology. For instance, in the early identification and diagnosis of voice problems, the automatic system for distinguishing healthy and diseased voices has gotten much attention. As a result, artificial intelligence-assisted voice analysis brings up new possibilities in healthcare. The work was aimed at assessing the utility of several automatic speech signal analysis methods for diagnosing voice disorders and suggesting a strategy for classifying healthy and diseased voices. The proposed framework integrates the efficacy of three voice characteristics: chroma, mel spectrogram, and mel frequency cepstral coefficient (MFCC). We also designed a deep neural network (DNN) capable of learning from the retrieved data and producing a highly accurate voice-based disease prediction model. The study describes a series of studies using the Saarbruecken Voice Database (SVD) to detect abnormal voices. The model was developed and tested using the vowels /a/, /i/, and /u/ pronounced in high, low, and average pitches. We also maintained the "continuous sentence" audio files collected from SVD to select how well the developed model generalizes to completely new data. The highest accuracy achieved was 77.49%, superior to prior attempts in the same domain. Additionally, the model attains an accuracy of 88.01% by integrating speaker gender information. The designed model trained on selected diseases can also obtain a maximum accuracy of 96.77% (cordectomy × healthy). As a result, the suggested framework is the best fit for the healthcare industry.

The Effect of Microphone Frequency Response on Spectral and Cepstral Measures of Voice: An Examination of Low-Cost Electret Headset Microphones

PURPOSE

The purpose of this study was to establish the frequency response of a selection of low-cost headset microphones that could be given to subjects for remote voice recordings and to examine the effect of microphone type and frequency response on key acoustic measures related to voice quality obtained from speech and vowel samples.

METHOD

The frequency responses of three low-cost headset microphones were evaluated using pink noise generated via a head-and-torso model. Each of the headset microphones was then used to record a series of speech and vowel samples prerecorded from 24 speakers who represented a diversity of sex, age, fundamental frequency (F _o), and voice quality types. Recordings were later analyzed for the following measures: smoothed cepstral peak prominence (CPP; dB), low versus high spectral ratio (L/H ratio; dB), CPP F _o (Hz), and cepstral spectral index of dysphonia (CSID).

RESULTS

The frequency response of the microphones under test was observed to have nonsignificant effects on measures of the CPP and CPP F _o, significant effects on the CSID in speech contexts, and strong and significant effects on the measure of spectral tilt (L/H ratio). However, the correlations between the various headset microphones and a reference precision microphone were excellent (rs > .90).

CONCLUSIONS

The headset microphones under test all showed the capability to track a wide range of diversity in the voice signal. Though the use of higher quality microphones that have demonstrated specifications is recommended for typical research and clinical purposes, low-cost electret microphones may be used to provide valid measures of voice, specifically when the same microphone and signal chain is used for the evaluation of pre- versus posttreatment change or intergroup comparisons.

Terapia de voz en el contexto de la pandemia covid-19; recomendaciones para la práctica clínica

INTRODUCTION

Since the beginning of the new pandemic, COVID-19 health services have had to face a new scenario. Voice therapy faces a double challenge, interventions using telepractice, and delivering rehabilitation services to a growing population of patients at risk of functional impairment related to the COVID-19 disease. Moreover, as COVID-19 is transmitted through droplets, it is critical to understand how to mitigate these risks during assessment and treatment.

OBJECTIVE

To promote safety, and effective clinical practice to voice assessment and rehabilitation in the pandemic COVID-19 context for speech-language pathologists.

METHODS

A group of 11 experts in voice and swallowing disorders from 5 different countries conducted a consensus recommendation following the American Academy of Otolaryngology-Head and Neck Surgery rules building a clinical guide for speech-language pathologists during this pandemic context.

RESULTS

The clinical guide provides 79 recommendations for clinicians in the management of voice disorders during the pandemic and includes advice from assessment, direct treatment, telepractice, and teamwork. The consensus was reached 95% for all topics.

CONCLUSION

This guideline should be taken only as recommendations; each clinician must attempt to mitigate the risk of infection and achieve the best therapeutic results taking into account the patient's particular reality.

Terapia Vocal No Contexto Da Pandemia Do Covid-19; Orientações Para A Prática Clínica

INTRODUCTION

Since the beginning of the new pandemic, Corona Virus Disease 2019 (COVID-19) health services have had to face a new scenario. Voice therapy faces a double challenge, interventions using telepractice, and delivering rehabilitation services to a growing population of patients at risk of functional impairment related to the COVID-19 disease. Moreover, as COVID-19 is transmitted through droplets, it is critical to understand how to mitigate these risks during assessment and treatment.

OBJECTIVE

To promote safety, and effective clinical practice to voice assessment and rehabilitation in the pandemic COVID-19 context for speech-language pathologists.

METHODS

A group of 11 experts in voice and swallowing disorders from five different countries conducted a consensus recommendation following the American Academy of Otolaryngology-Head and Neck Surgery rules building a clinical guide for speech-language pathologists during this pandemic context.

RESULT

The clinical guide provides 79 recommendations for clinicians in the management of voice disorders during the pandemic and includes advice from assessment, direct treatment, telepractice, and teamwork. The consensus was reached 95% for all topics.

CONCLUSION

This guideline should be taken only as recommendation; each clinician must attempt to mitigate the risk of infection and achieve the best therapeutic results taking into account the patient's particular reality.

Voice Therapy in the Context of the COVID-19 Pandemic: Guidelines for Clinical Practice

INTRODUCTION

Since the beginning of the new pandemic, COVID-19 health services have had to face a new scenario. Voice therapy faces a double challenge, interventions using telepractice, and delivering rehabilitation services to a growing population of patients at risk of functional impairment related to the COVID-19 disease. Moreover, as COVID-19 is transmitted through droplets, it is critical to understand how to mitigate these risks during assessment and treatment.

OBJECTIVE

To promote safety, and effective clinical practice to voice assessment and rehabilitation in the pandemic COVID-19 context for speech-language pathologists.

METHODS

A group of 11 experts in voice and swallowing disorders from five different countries conducted a consensus recommendation following the American Academy of Otolaryngology-Head and Neck Surgery rules building a clinical guide for speech-language pathologists during this pandemic context.

RESULTS

The clinical guide provides 65 recommendations for clinicians in the management of voice disorders during the pandemic and includes advice from assessment, direct treatment, telepractice, and teamwork. The consensus was reached 95% for all topics.

CONCLUSION

This guideline should be taken only as recommendation; each clinician must attempt to mitigate the risk of infection and achieve the best therapeutic results taking into account the patient's particular reality.

Accuracy of Acoustic Measures of Voice via Telepractice Videoconferencing Platforms

Purpose Telepractice improves patient access to clinical care for voice disorders. Acoustic assessment has the potential to provide critical, objective information during telepractice, yet its validity via telepractice is currently unknown. The current study investigated the accuracy of acoustic measures of voice in a variety of telepractice platforms. Method Twenty-nine voice samples from individuals with dysphonia were transmitted over six video conferencing platforms (Zoom with and without enhancements, Cisco WebEx, Microsoft Teams, Doxy.me, and VSee Messenger). Standard time-, spectral-, and cepstral-based acoustic measures were calculated. The effect of transmission condition on each acoustic measure was assessed using repeated-measures analyses of variance. For those acoustic measures for which transmission condition was a significant factor, linear regression analysis was performed on the difference between the original recording and each telepractice platform, with the overall severity of dysphonia, Internet speed, and ambient noise from the transmitter as predictors. Results Transmission condition was a statistically significant factor for all acoustic measures except for mean fundamental frequency (f o). Ambient noise from the transmitter was a significant predictor of differences between platforms and the original recordings for all acoustic measures except f o measures. All telepractice platforms affected acoustic measures in a statistically significantly manner, although the effects of platforms varied by measure. Conclusions Overall, measures of f o were the least impacted by telepractice transmission. Microsoft Teams had the least and Zoom (with enhancements) had the most pronounced effects on acoustic measures. These results provide valuable insight into the relative validity of acoustic measures of voice when collected via telepractice. Supplemental Material https://doi.org/10.23641/asha.14794812.

Comparing acoustic analyses of speech data collected remotely

Face-to-face speech data collection has been next to impossible globally as a result of the COVID-19 restrictions. To address this problem, simultaneous recordings of three repetitions of the cardinal vowels were made using a Zoom H6 Handy Recorder with an external microphone (henceforth, H6) and compared with two alternatives accessible to potential participants at home: the Zoom meeting application (henceforth, Zoom) and two lossless mobile phone applications (Awesome Voice Recorder, and Recorder; henceforth, Phone). F0 was tracked accurately by all of the devices; however, for formant analysis (F1, F2, F3), Phone performed better than Zoom, i.e., more similarly to H6, although the data extraction method (VoiceSauce, Praat) also resulted in differences. In addition, Zoom recordings exhibited unexpected drops in intensity. The results suggest that lossless format phone recordings present a viable option for at least some phonetic studies.

A Field-Based Approach to Establish Normative Acoustic Data for Healthy Female Voices

Purpose The primary aim of this study was to obtain high-quality acoustic normative data in natural field environments for female voices. A secondary aim was to examine acoustic measurement variability in field environments. Method This study employed a within-subject repeated-measures experimental design that included 45 young female adults with normal voices. Participants were stratified by age (18-23, 24-29, and 30-35 years). After initial evaluation and instruction, participants completed voice recordings during seven consecutive days using a standard protocol, including both connected speech and sustained vowels. Thirty-two cepstral-, spectral-, and time-based acoustic measures were acquired using Praat and the Analysis of Dysphonia in Speech and Voice. Results Among the 958 total recordings, greater than 90% satisfied inclusion criteria based on protocol compliance, peak clipping, and signal-to-noise ratio. Significant differences were observed for age (p < .05). For 19 acoustic measures, values improved significantly as signal-to-noise ratio increased. Cepstral- and spectral-based measures demonstrated less measurement variability as compared with time-based measures. Conclusions With adequate training, field audio recordings represent a viable option for clinical voice management. The significant age effects observed in this study support the need for more specific criteria when collecting and applying normative data. Cepstral- and spectral-based measures demonstrated the least measurement variability. This study provides additional evidence for multiparameter acoustic voice measurement, specifically toward ecologically valid sampling in natural environments. Future studies should expand on these findings in other populations with normal and disordered voices.

Accuracy of Acoustic Voice Quality Index Captured With a Smartphone - Measurements With Added Ambient Noise

OBJECTIVE

To evaluate the accuracy of Acoustic Voice Quality Index (AVQI) measures obtained from voice recordings simultaneously using oral and smartphone microphones in a sound-proof room, and to compare them with AVQIs obtained from the same smartphone voice recordings with added ambient noise.

METHODS

A study group of 183 subjects with normal voices (n = 86) and various voice disorders (n = 97) was asked to read aloud a standard text and sustain the vowel /a/. The controlled ambient noise averaged at 29.61 dB SPL was added digitally to the smartphone voice recordings. Repeated measures analysis of variances (ANOVA) with Greenhouse-Geiser correction was used to evaluate AVQI changes within subjects. To evaluate the level of agreement between AVQI measurements obtained from different voice recordings Bland-Altman plots were used.

RESULTS

Repeated measures ANOVA showed that differences among AVQI results obtained from voice recordings done with oral studio microphone, recordings done with a smartphone microphone, and recordings done with a smartphone microphone with added ambient noise were not statistically significant (P = 0.07). No significant systemic differences and acceptable level of random errors in AVQI measurements of voice recordings made with oral and smartphone microphones (including added noise) were revealed.

CONCLUSION

The AVQI measures obtained from smartphone microphones voice recordings with experimentally added ambient noise revealed an acceptable agreement with results of oral microphone recordings, thus suggesting the suitability of smartphone microphone recordings performed even in the presence of acceptable ambient noise for estimation of AVQI.

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.

Evaluation of Speech-Based Digital Biomarkers: Review and Recommendations

Speech represents a promising novel biomarker by providing a window into brain health, as shown by its disruption in various neurological and psychiatric diseases. As with many novel digital biomarkers, however, rigorous evaluation is currently lacking and is required for these measures to be used effectively and safely. This paper outlines and provides examples from the literature of evaluation steps for speech-based digital biomarkers, based on the recent V3 framework (Goldsack et al., 2020). The V3 framework describes 3 components of evaluation for digital biomarkers: verification, analytical validation, and clinical validation. Verification includes assessing the quality of speech recordings and comparing the effects of hardware and recording conditions on the integrity of the recordings. Analytical validation includes checking the accuracy and reliability of data processing and computed measures, including understanding test-retest reliability, demographic variability, and comparing measures to reference standards. Clinical validity involves verifying the correspondence of a measure to clinical outcomes which can include diagnosis, disease progression, or response to treatment. For each of these sections, we provide recommendations for the types of evaluation necessary for speech-based biomarkers and review published examples. The examples in this paper focus on speech-based biomarkers, but they can be used as a template for digital biomarker development more generally.

Smartphone Use in Clinical Voice Recording and Acoustic Analysis: A Literature Review

OBJECTIVE

With the increase of smartphone use and availability over the last decade, mobile healthcare applications have become more accessible. Many of these applications allow users to track behaviors and goals, and acquire feedback and information while on the go. Recent studies appearing in the literature suggest that smartphones may offer a means of augmenting clinical voice assessment by recording individuals with voice disorders outside the clinic for the purpose of extracting acoustic characteristics. This review examines the effectiveness of smartphones in clinical voice assessment and treatment, as reported in the current literature.

METHODS

The PubMed database was searched using a combination and variation of different term related to smartphones, voice, and recording apps, in order to find articles that address the role of smartphones in clinical voice recording and assessment.

RESULTS AND CONCLUSION

Six studies published in the last 3 years were reviewed and examined in terms of types of device and operating systems used, types of subjects and disorders studied, voice parameters extracted, and microphones used. Considerations such as impact of environmental noise, and privacy and security issues are also examined. While smartphones and mobile apps have the potential to be valuable tools in voice assessment outside the clinic, further efforts are needed for them to be effectively used in a clinical setting.

Objective Acoustic Quantification of Perceived Voice Tremor Severity

Purpose This study compared auditory-perceptual measures of presence/absence and severity of vocal tremor to acoustic markers of vocal tremor. The validity (both concurrent and diagnostic) of various acoustic markers of vocal tremor was also assessed. Method Fifty-six midvowel sustained [a:] recordings were selected to yield a representative convenience sample of vocal tremor. After training with 10 synthesized samples, 4 female audiologists rated these samples on "voice tremor severity" on a continuous 10-cm scale. Afterward, 15 randomly selected recordings were presented a 2nd time for intrarater reliability assessment. Customized audio signal processing in Praat yielded 12 acoustic measures of rate, extent and perturbation of fundamental frequency (f ₀), and intensity level (IL) modulation. Enter-type multiple linear regression analysis was applied to weight and combine these acoustic variables into an acoustic model of vocal tremor severity. Results After removing the vocal tremor severity ratings of 1 of the audiologists because of insufficient intra- and interrater reliability, mean single-measures consistency-type intraclass correlation coefficients equaled .83 within raters and .72 between raters. Correlation between mean ratings and the 12 acoustic markers ranged from .76 for median extent of f ₀ modulation to .11 for rate of IL modulation. Correlation between mean ratings and the acoustic model was .89. Analysis of this model's receiver operating characteristics yielded an area under receiver operating characteristic curve of .93, denoting sensitivity of .87 and specificity of .91. Conclusions This study demonstrated that auditory-perceptual ratings of vocal tremor severity are guided primarily by f ₀ and IL modulation extent, less by modulation perturbation, and least by modulation rate. The acoustic model covering all these modulation properties yielded acceptable results in terms of both concurrent and diagnostic validity. However, external cross-validation of this model is warranted before applying it in clinical voice/speech assessment.

Assessing voice health using smartphones: bias and random error of acoustic voice parameters captured by different smartphone types

BACKGROUND

Occupational voice problems constitute a serious public health issue with substantial financial and human consequences for society. Modern mobile technologies such as smartphones have the potential to enhance approaches to prevention and management of voice problems. This paper addresses an important aspect of smartphone-assisted voice care: the reliability of smartphone-based acoustic analysis for voice health state monitoring.

AIM

To assess the reliability of acoustic parameter extraction for a range of commonly used smartphones by comparison with studio recording equipment.

METHODS & PROCEDURES

Twenty-two vocally healthy speakers (12 female, 10 male) were recorded producing sustained vowels and connected speech under studio conditions using a high-quality studio microphone and an array of smartphones. For both types of utterance, Bland-Altman analysis was used to assess overall reliability for mean F0, cepstral peak prominence (CPPS), Jitter (RAP) and Shimmer %.

OUTCOMES & RESULTS

Analysis of the systematic and random error indicated significant bias for CPPS across both sustained vowels and passage reading. Analysis of the random error of the devices indicated that that mean F0 and CPPS showed acceptable random error size, while jitter and shimmer random error was judged as problematic.

CONCLUSIONS & IMPLICATIONS

Confidence in the feasibility of smartphone-based voice assessment is increased by the experimental finding of high levels of reliability for some clinically relevant acoustic parameters, while the use of other parameters is discouraged. We also challenge the practice of using statistical tests (e.g., t-tests) for measurement reliability assessment.

The Current State and Future Possibilities of Mobile Phone "Voice Analyser" Applications, in Relation to Otorhinolaryngology

BACKGROUND

A large proportion of the population suffers from voice disorders. The use of mobile phone technology in healthcare is increasing, and this includes applications that can analyze voice.

OBJECTIVE

This study aimed to review the potential for voice analyzer applications to aid the management of voice disorders.

METHODS

A literature search was conducted yielding eight studies which were further analyzed.

RESULTS

Seven out of the eight studies concluded that smartphone assessments were comparable to current techniques. Nevertheless there remained some common issues with using applications such as; voice parameters used; voice pathology tested; smartphone software consistency and microphone specifications.

CONCLUSIONS

It is clear that further developments are required before a mobile application can be used widely in voice analysis. However, promising results have been obtained thus far, and the benefits of mobile technology in this field, particularly in voice rehabilitation, warrant further research into its widespread implementation.