Acoustic Perturbation Measures Improve with Increasing Vocal Intensity in Individuals With and Without Voice Disorders

Effects of Speech Characteristics on Electroglottographic and Instrumental Acoustic Voice Analysis Metrics in Women With Structural Dysphonia Before and After Treatment

PURPOSE

Literature suggests a dependency of the acoustic metrics, smoothed cepstral peak prominence (CPPS) and harmonics-to-noise ratio (HNR), on human voice loudness and fundamental frequency (F0). Even though this has been explained with different oscillatory patterns of the vocal folds, so far, it has not been specifically investigated. In the present work, the influence of three elicitation levels, calibrated sound pressure level (SPL), F0 and vowel on the electroglottographic (EGG) and time-differentiated EGG (dEGG) metrics hybrid open quotient (OQ), dEGG OQ and peak dEGG, as well as on the acoustic metrics CPPS and HNR, was examined, and their suitability for voice assessment was evaluated.

METHOD

In a retrospective study, 29 women with a mean age of 25 years (± 8.9, range: 18-53) diagnosed with structural vocal fold pathologies were examined before and after voice therapy or phonosurgery. Both acoustic and EGG signals were recorded simultaneously during the phonation of the sustained vowels /ɑ/, /i/, and /u/ at three elicited levels of loudness (soft/comfortable/loud) and unconstrained F0 conditions.

RESULTS

A linear mixed-model analysis showed a significant effect of elicitation effort levels on peak dEGG, HNR, and CPPS (all p < .01). Calibrated SPL significantly influenced HNR and CPPS (both p < .01). Furthermore, F0 had a significant effect on peak dEGG and CPPS (p < .0001). All metrics showed significant changes with regard to vowel (all p < .05). However, the treatment had no effect on the examined metrics, regardless of the treatment type (surgery vs. voice therapy).

CONCLUSIONS

The value of the investigated metrics for voice assessment purposes when sampled without sufficient control of SPL and F0 is limited, in that they are significantly influenced by the phonatory context, be it speech or elicited sustained vowels. Future studies should explore the diagnostic value of new data collation approaches such as voice mapping, which take SPL and F0 effects into account.

Voice self-assessment in individuals with Parkinson's Disease as compared to general voice disorders

BACKGROUND

Individuals with Parkinson's Disease (IwPD) often fail to adjust their voice in different situations, without awareness of this limitation. Clinicians use self-report questionnaires that are typically designed for individuals with General Voice Disorders (GVD) in the vocal assessment of IwPD. However, these instruments may not consider that IwPD have a reduced self-perception of their vocal deficits. This study aimed to compare self-reported vocal symptoms and voice loudness between IwPD and GVD.

METHODS

28 IwPD and 26 with GVD completed the Voice Symptom Scale (VoiSS) questionnaire to evaluate their voice self-perception. Vocal loudness (dB) was also assessed. Univariate and multivariate analyses were used to compare the outcomes from these measures between the two groups. Principal Component Analysis and Hierarchical Clustering Analysis were applied to explore data patterns related to voice symptoms.

RESULTS

IwPD reported significantly fewer vocal symptoms than those with GVD in all VoiSS questionnaire domains. Multivariate principal component analysis found no significant correlations between VoiSS scores and participant similarities in voice measures. Despite experiencing hypophonia, IwPD scored lower in all VoiSS domains but still fell in the healthy voice range. Hierarchical Clustering Analysis grouped participants into three distinct categories, primarily based on age, vocal loudness, and VoiSS domain scores, distinguishing between PD and GVD individuals.

CONCLUSIONS

IwPD reported fewer vocal symptoms than GVD. The voice self-assessment seems to be unreliable to assess vocal symptoms in IwPD, at least regarding loudness. New self-report instruments tailored to PD individuals are needed due to their particular voice characteristics.

Effects on Voice Quality of Thyroidectomy: A Qualitative and Quantitative Study Using Voice Maps

OBJECTIVES

This study aims to explore the effects of thyroidectomy-a surgical intervention involving the removal of the thyroid gland-on voice quality, as represented by acoustic and electroglottographic measures. Given the thyroid gland's proximity to the inferior and superior laryngeal nerves, thyroidectomy carries a potential risk of affecting vocal function. While earlier studies have documented effects on the voice range, few studies have looked at voice quality after thyroidectomy. Since voice quality effects could manifest in many ways, that a priori are unknown, we wish to apply an exploratory approach that collects many data points from several metrics.

METHODS

A voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and 2months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics.

RESULTS

After thyroidectomy, statistically significant changes consistent with a worsening of voice quality were observed in most metrics. For all individual metrics, however, the effect sizes were too small to be clinically relevant. Statistical clustering of the metrics helped to clarify the nature of these changes. While partial thyroidectomy demonstrated greater uniformity than did total thyroidectomy, the type of perioperative damage had no discernible impact on voice quality.

CONCLUSIONS

Changes in voice quality after thyroidectomy were related mostly to increased phonatory instability in both the acoustic and EGG metrics. Clustered voice metrics exhibited a higher correlation to voice complaints than did individual voice metrics.

Immediate effects of the semi-occluded bubble mask technique using VocalFeel® device as vocal warm-up in singers

OBJECTIVE

The present study aims at investigating the immediate effects of the Semi-Occluded Bubble Mask Technique (SOBM) performed with the device VocalFeel® as a vocal warm-up in a group of professional singers.

STUDY DESIGN

A randomized controlled study was carried out.

METHODS

Forty-four vocally healthy professional singers were randomly divided into two groups on recruitment: an experimental group and a control group. The same vocal warm-up exercise was performed by the experimental group with the SOMB technique and by the control group without semi-occlusion. Self assessments, acoustic analysis and aerodynamic analysis of Peak Nasal Inspiratory Flows (PNIF) and Peak Oral Inspiratory Flows (POIF) were performed.

RESULTS

Significant improvements after the SOBM technique were detected in the experimental group concerning some acoustic parameters (Jitt%; Shimm%) and aerodynamic measures (PNIF and POIF). No significant improvements after the warm-up exercise were observed in the control group. Significant differences between the experimental and the control group were found for ΔJitt%, ΔShimm%, ΔNHR, ΔPOIF and self assessments.

CONCLUSIONS

The results of the present study support the efficacy of a vocal warm-up performed with the SOBM technique using VocalFeel® device in terms of acoustic quality, aerodynamic measures and perceived phonatory comfort in professional singers.

The Efficacy of the NHS Waterpipe in Superficial Hydration for People With Healthy Voices: Effects on Acoustic Voice Quality, Phonation Threshold Pressure and Subjective Sensations

OBJECTIVES

This study examined the efficacy of the NHS waterpipe as a superficial hydration treatment in voice production in healthy young women.

STUDY DESIGN

This is a prospective, single-blind, within- and between-subject experimental design.

METHODS

Thirty six female university students (mean age 24.6 years, range 19-45 years) were recruited to the study. Participants were randomized to two experimental groups (E1 and E2) and a control group. E1 underwent hydration treatment with the NHS waterpipe filled with 0.9% saline that was immersed in a cup of heated water. E2 underwent a similar treatment but without heated immersion. The control group received no treatment. Acoustic Voice Quality Index (AVQI v03.01) and its subparameters, phonation threshold pressure, self-perceived phonatory effort and sensation of throat dryness was measured at three time points (before the intervention and immediately and 15 minutes after it).

RESULTS

The Tilt of the AVQI's subparameters increased significantly in the E1 (P = 0.027) and E2 groups (P = 0.027) after the intervention. Furthermore, the E1 group had significantly lower harmonics-to-noise-ratio values at the third measurement point compared to the E2 group (P = 0.023). These findings may result from fluid transported to the vocal fold level. The sensations of throat dryness decreased in the E1 (P = 0.001) and E2 groups (P < 0.0005) after the intervention. Perceived phonatory effort decreased statistically significantly at the final measurement point in the E1 (P = 0.002) and E2 (P = 0.031) groups. No variables changed in the control group.

CONCLUSIONS

The waterpipe seems to be efficient in hydrating vocal folds on single use. It seems to be more efficient when employed with a hot water bath, albeit slightly impairing some acoustic values in the short term. Without the heated fluid, it still seems to decrease sensations of throat dryness and affect acoustic voice quality. The waterpipe does not seem to have an effect on phonation threshold pressure, and it seems to lower self-perceived effort just as efficiently whether the waterpipe is employed using a hot water bath or not. Further research is needed to prove the efficacy of long-term usage and usage with voice patients.

Validation of the Acoustic Breathiness Index in Speakers of Finnish Language

Breathiness (perception of turbulence noise in the voice) is one of the major components of hoarseness in dysphonic voices. This study aims to validate a multiparameter analysis tool, the Acoustic Breathiness Index (ABI), for quantification of breathiness in the speaking voice, including both sustained vowels and continuous speech. One hundred and eight speakers with dysphonia (28 M, 80 F, mean age 50, SD 15.4 years) and 87 non-dysphonic controls (18 M, 69 F, mean age 42, SD 14 years) volunteered as participants. They read a standard text and sustained vowel /a:/. Acoustic recordings were made using a head-mounted microphone. Acoustic samples were evaluated perceptually by nine voice experts of different backgrounds (speech therapists, vocologists and laryngologists). Breathiness (B) from the GRBAS scale was rated. Headphones were used in the perceptual analysis. The dysphonic and non-dysphonic speakers differed significantly from each other in the auditory perceptual evaluation of breathiness. A significant difference was also found for ABI, which had a mean value of 2.26 (SD 1.15) for non-dysphonic and 3.07 (SD 1.75) for dysphonic speakers. ABI correlated strongly with B (rs = 0.823, p = 0.01). ABI's power to distinguish the groups was high (88.6%). The highest sensitivity and specificity of ABI (80%) was obtained at threshold value 2.68. ABI is a valid tool for differentiating breathiness in non-dysphonic and dysphonic speakers of Finnish.

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.

High and Wide: An In Silico Investigation of Frequency, Intensity, and Vibrato Effects on Widely Applied Acoustic Voice Perturbation and Noise Measures

OBJECTIVES

This in silico study explored the effects of a wide range of fundamental frequency (fo), source-spectrum tilt (SST), and vibrato extent (VE) on commonly used frequency and amplitude perturbation and noise measures.

METHOD

Using 53 synthesized tones produced in Madde, the effects of stepwise increases in fo, intensity (modeled by decreasing SST), and VE on the PRAAT parameters jitter % (local), relative average perturbation (RAP) %, shimmer % (local), amplitude perturbation quotient 3 (APQ3) %, and harmonics-to-noise ratio (HNR) dB were investigated. A secondary experiment was conducted to determine whether any fo effects on jitter, RAP, shimmer, APQ3, and HNR were stable. A total of 10 sinewaves were synthesized in Sopran from 100 to 1000 Hz using formant frequencies for /a/, /i/, and /u/-like vowels, respectively. All effects were statistically assessed with Kendall's tau-b and partial correlation.

RESULTS

Increasing fo resulted in an overall increase in jitter, RAP, shimmer, and APQ3 values, respectively (P < 0.01). Oscillations of the data across the explored fo range were observed in all measurement outputs. In the Sopran tests, the oscillatory pattern seen in the Madde fo condition remained and showed differences between vowel conditions. Increasing intensity (decreasing SST) led to reduced pitch and amplitude perturbation and HNR (P < 0.05). Increasing VE led to lower HNR and an almost linear increase of all other measures (P < 0.05).

CONCLUSION

These novel data offer a controlled demonstration for the behavior of jitter (local) %, RAP %, shimmer (local) %, APQ3 %, and HNR (dB) when varying fo, SST, and VE in synthesized tones. Since humans will vary in all of these aspects in spoken language and vowel phonation, researchers should take potential resonance-harmonics type effects into account when comparing intersubject or preintervention and postintervention data using these measures.

Classical singers are also proficient in non-classical singing

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

Differences and Reliability of Linear and Nonlinear Acoustic Measures as a Function of Vocal Intensity in Individuals With Voice Disorders

PURPOSE

Linear acoustic indices are significantly influenced by speaking voice intensity. The main aim of this work was to compare acoustic measures based on linear and nonlinear models in different speaking voice intensity levels and to analyze the reliability of those measures in different intensity levels in subjects with voice disorders.

METHODS

435 samples from subjects (314 women, 121 men with a mean age of 41.07 ± 13.73) diagnosed with various voice disorders were used. In total, 17 acoustic measures were derived from the vowel /ɛ/ sustained at three intensity levels (soft, comfortable, and loud). Five were linear (standard deviation of the fundamental frequency (f0), jitter, shimmer, harmonics-to-noise ratio (HNR) and smoothed cepstral peak prominence (CPPS)), and twelve were nonlinear measures, namely correlation dimension (D2), correlation entropy (H2), first minimum of the mutual information function (FMMI), relative entropy (ENTR-R), largest Lyapunov exponent (Lyap), determinism (DET), transitivity, mean diagonal line length (Lmed), Shannon entropy (ENTR-S), mean length of vertical structures, also known as trapping time (TT), laminarity (LAM) and recurrence period density entropy (RPDE). Differences between speaking voice intensity levels were assessed by Friedman's test and Nemenyi as posthoc test. Intraclass correlation coefficient was used to investigate if each acoustic measure remains in agreement (reliability) between different voice intensity levels.

RESULTS

There were significant differences in all acoustic measures about vocal intensity level (P < 0.001). Intraclass correlation coefficient was very good for HNR (>0.61) and good for Lyap, DET, ENTR-S, Lmed, RPDE, and TT (0.41-0.60).

CONCLUSIONS

All acoustic measures varied as a function of vocal intensity in voice disordered adults, while this relation was different for linear and nonlinear measures. Only the measures HNR, Lyap, DET, ENTR-S, Lmed, RPDE and TT had an acceptable reliability between different voice intensity levels. Therefore, patient`s voice SPL should be controlled or indicated during acoustic vocal assessment.

It Sounds like It Feels: Preliminary Exploration of an Aeroacoustic Diagnostic Protocol for Singers

To date, no established protocol exists for measuring functional voice changes in singers with subclinical singing-voice complaints. Hence, these may go undiagnosed until they progress into greater severity. This exploratory study sought to (1) determine which scale items in the self-perceptual Evaluation of Ability to Sing Easily (EASE) are associated with instrumental voice measures, and (2) construct as proof-of-concept an instrumental index related to singers' perceptions of their vocal function and health status. Eighteen classical singers were acoustically recorded in a controlled environment singing an /a/ vowel using soft phonation. Aerodynamic data were collected during a softly sung /papapapapapapa/ task with the KayPENTAX Phonatory Aerodynamic System. Using multi and univariate linear regression techniques, CPPS, vibrato jitter, vibrato shimmer, and an efficiency ratio (SPL/PSub) were included in a significant model (p < 0.001) explaining 62.4% of variance in participants' composite scores of three scale items related to vocal fatigue. The instrumental index showed a significant association (p = 0.001) with the EASE vocal fatigue subscale overall. Findings illustrate that an aeroacoustic instrumental index may be useful for monitoring functional changes in the singing voice as part of a multidimensional diagnostic approach to preventative and rehabilitative voice healthcare for professional singing-voice users.

Effect of Wearing Different Masks on Acoustic, Aerodynamic, and Formant Parameters

OBJECTIVE

This study aimed to investigate the effects of different types of masks on acoustic, aerodynamic, and formant parameters in healthy people.

METHODS

Our study involved 30 healthy participants, 15 of each gender, aged 20-40 years. The tests were conducted under four conditions: without a mask, after wearing a surgical mask, after wearing a head-mounted N95 mask, and after wearing an ear-mounted N95 mask. Voice recording was done with the mask on. The acoustic parameters include mean fundamental frequency (F0), mean intensity, percentage of jitter (local), percentage of shimmer (local), mean noise to harmonic ratio (NHR), aerodynamic parameter, maximum phonation time (MPT), and formant parameters (/a/, /i/, /u/ three vowels F1, F2).

RESULTS

The main effect of mask type was significant in MPT, mean F0, mean HNR, /a/F1, /a/F2, /i/F2. However, the effect sizes and power in /a/F2, /i/F2 were low. MPT, mean F0 and mean HNR significantly increased and /a/F1 significantly decreased after wearing the head-mounted n95 mask. The mean F0 and mean HNR increased significantly after wearing the ear-mounted n95 mask. No significant changes were observed in parameters after wearing the surgical mask in this study. When the statistics are performed separately for males and females, the results obtained are similar to those previously obtained for unspecified males and females.

CONCLUSION

After wearing the surgical mask, this study found insignificant changes in mean F0, jitter (local), shimmer (local), mean NHR, mean intensity, MPT, and the vowels F1 and F2. This may be due to the looser design of the surgical mask and the relatively small attenuation of sound. N95 masks have a greater effect on vocalization than surgical masks and may cause changes in F0 and HNR after wearing an N95 mask. In the present study, no significant changes in jitter and shimmer were observed after wearing the mask. In addition, there was a significant reduction in /a/F1 after wearing the N95 headgear mask may owing to its high restriction of jaw mobility. In future studies, the change in jaw movement amplitude after wearing the mouthpiece can be added to investigate.

Evaluation of Immediate Effects of Straw Phonation Exercise and Determination of the Ideal Performance Time in Healthy Adults

PURPOSE

The ideal performance time of straw phonation exercise, one of the semi-occluded vocal tract exercise types, in which optimal effects are seen in healthy voices is still unknown. The aim of this study was to investigate the immediate effect of straw phonation exercise in healthy adults after 1, 3, 5, 7, and 10 minutes, considering: acoustic parameters, electroglottographic parameters, auditory-perceptual general voice quality, the participants' self-assessment regarding vocal effort, and laryngeal discomfort during exercise.

METHODS

This study included 69 participants (35 women, 34 men) with a healthy voice. Participants performed the exercise with straw for a total of 10 minutes. The data were collected before (m0) and immediately after exercises at the first (m1), third (m3), fifth (m5), seventh (m7), and tenth (m10) minutes of performance using sustained emission of vowel /a/ and a sentence.

RESULTS

There was an increase in the fundamental frequency at m7 and a decrease in the shimmer from m5 in men. The sound pressure level increased at m5 and m10 in women and from m1 in men. The Acoustic Voice Quality Index score decreased at m5 in men. The mean average closed quotient decreased at m10 in women. Auditory-perceptual general voice quality was optimal at m3 in women and at m5 in men, it deteriorated at m7 in women and at m10 in men. The vocal effort during the exercise increased at m7 in women and at m10 in men. The laryngeal discomfort during the exercise increased for both sexes at m10.

CONCLUSIONS

The straw phonation exercise in healthy individuals promoted optimal effects on voice quality after 5 and 7 minutes for men and 3 and 5 minutes for women. Prolongation of the exercise time causes negative effects on voice quality and an increase in vocal effort and laryngeal discomfort presented by the participants.

Normative Values of Cepstral Peak Prominence Measures in Typical Speakers by Sex, Speech Stimuli, and Software Type Across the Life Span

PURPOSE

The purpose of this study was to determine normative values for cepstral peak prominence measures across the life span as a function of sex using clinically relevant stimuli (/ɑ/, /i/, and two sentences of The Rainbow Passage) and two commonly used software types: Praat (Version 6.0.50) and Analysis of Dysphonia in Speech and Voice (ADSV).

METHOD

One hundred fifty speakers (75 males, 75 females; evenly distributed into three age groups) without voice disorders aged 18-91 years were recorded via headset microphone in a sound-treated booth. Cepstral measures were analyzed using common analysis methods in Praat and ADSV by sex, stimuli, and software type. Kruskal-Wallis tests and post hoc Mood's Median tests for significant factors were performed on cepstral measures to assess the effects of age group, sex, stimuli, and software type.

RESULTS

The results revealed statistically significant effects of sex, stimuli, and software type on cepstral measures, but no statistical effect of age group on cepstral values. Females had lower average cepstral values compared to males. Across stimuli, the highest average cepstral measure was found for sustained /ɑ/, followed by sustained /i/, and then of the two sentences of The Rainbow Passage. Average cepstral measures in Praat were higher than those from ADSV.

CONCLUSIONS

The current work did not find a statistical effect of age group on cepstral values; thus, normative cepstral values were reported by sex, stimuli, and software type. Future work should examine the applicability of these normative values for discriminating speakers with and without voice disorders.

How Does Long Term Use of Surgical Face Mask Affect the Voice in Normophonic Subjects?

OBJECTIVES

To assess the effects of the longterm-use of surgical face mask (SFM) on acoustic and auditory-perceptual voice parameters in normophonic subjects without any known risk factor related to voice disorders.

MATERIALS AND METHODS

Of 73 normophonic subjects who were previously included in a couple of studies before the COVID-19 outbreak, 25 people (18 female and 7 male) who were free of any known risk factor related to voice disorders during the outbreak were re-evaluated to assess the long-term effect of SFM on voice by using acoustic (mean F0, Jitter-local, Shimmer-local, Cepstral Peak Prominence (CPP), Noise to Harmonic Ratio (NHR), maximum phonation time (MPT)) and auditory-perceptual (Consensus Auditory-Perceptual Evaluation of Voice, CAPE-V) parameters and those data found in SFM period were compared with the previous (preSFM) data. MPT and acoustic data were analyzed by PRAAT software.

RESULTS

It was seen that the mean F0 value presented a significant increase, while Jitter-local and Intensity values revealed a significant decrease in females after 2 years pass with SFM use (average 22.52 ± 0.18 months).In males, only a significant decrease in Jitter-local was detected.

CONCLUSIONS

This study is the first longitudinal investigation on the effects of SFM use on acoustic and auditory-perceptual measures of voice. The data in this study, revealed that long-term use of SFM would not appear to be negatively affecting the acoustic parameters of the voice in normophonic subjects (particularly females) without any related risk factors such as tobacco use, reflux, and etc.

Community Choir Improves Vocal Production Measures in Individuals Living with Parkinson's Disease

OBJECTIVES

Parkinson's disease (PD) is a neurodegenerative disease leading to motor impairments and dystonia across diverse muscle groups including vocal muscles. The vocal production challenges associated with PD have received considerably less research attention than the primary gross motor symptoms of the disease despite having a substantial effect on quality of life. Increasingly, people living with PD are discovering group singing as an asset-based approach to community building that is purported to strengthen vocal muscles and improve vocal quality.

STUDY DESIGN/METHODS

The present study investigated the impact of community choir on vocal production in people living with PD across two sites. Prior to and immediately following a 12-week community choir at each site, vocal testing included a range of vocal-acoustic measures, including lowest and highest achievable pitch, duration of phonation, loudness, jitter, and shimmer.

RESULTS

Results showed that group singing significantly improved some, though not all, measures of vocal production. Group singing improved lowest pitch (both groups), duration (both groups), intensity (one group), and jitter (one group) and shimmer (both groups).

CONCLUSIONS

These findings support community choir as a feasible and scalable complementary approach to managing vocal production challenges associated with PD.

Speaking with a KN95 face mask: a within-subjects study on speaker adaptation and strategies to improve intelligibility

Mask-wearing during the COVID-19 pandemic has prompted a growing interest in the functional impact of masks on speech and communication. Prior work has shown that masks dampen sound, impede visual communication cues, and reduce intelligibility. However, more work is needed to understand how speakers change their speech while wearing a mask and to identify strategies to overcome the impact of wearing a mask. Data were collected from 19 healthy adults during a single in-person session. We investigated the effects of wearing a KN95 mask on speech intelligibility, as judged by two speech-language pathologists, examined speech kinematics and acoustics associated with mask-wearing, and explored KN95 acoustic filtering. We then considered the efficacy of three speaking strategies to improve speech intelligibility: Loud, Clear, and Slow speech. To inform speaker strategy recommendations, we related findings to self-reported speaker effort. Results indicated that healthy speakers could compensate for the presence of a mask and achieve normal speech intelligibility. Additionally, we showed that speaking loudly or clearly-and, to a lesser extent, slowly-improved speech intelligibility. However, using these strategies may require increased physical and cognitive effort and should be used only when necessary. These results can inform recommendations for speakers wearing masks, particularly those with communication disorders (e.g., dysarthria) who may struggle to adapt to a mask but can respond to explicit instructions. Such recommendations may further help non-native speakers and those communicating in a noisy environment or with listeners with hearing loss.

Mitigating Dysphonia, Pain, and Vocal Handicap after Violent Video Game Voice Overs: A Pilot Investigation into Vocal Combat Technique Training

OBJECTIVE

to investigate how the Vocal Combat Technique (VCT) may mitigate vocal symptoms in voice over actors using vocal violence.

METHODS

Five voice over actors (3 male, 2 females, Mean = 29.6 years) completed two study sessions of 45 minutes-to-1 hour of vocally violent voice over work held approximately 4 weeks apart. During session one, participants completed voice over work as they typically would, whereas they received 3-hours of VCT training to improve/assist in healthy vocal techniques prior to session two. Pre- and post-session measures for both sessions included self-perceptual ratings of vocal symptoms, auditory-perceptual evaluation, and traditional acoustic measures of frequency and perturbation.

RESULTS

Participants showed substantial mitigating effects of VCT training on acoustic perturbation measures (jitter, shimmer, harmonics-to-noise ratio), and self-ratings of vocal symptoms (Vocal-Handicap Index-10, McGill Pain Scale for vocal discomfort, and Evaluation of the Ability to Sing Easily) with calculated medium to large effect sizes (d = 0.61-1.95). There were no changes in auditory perceptual ratings across sessions.

CONCLUSION

Our pilot investigation yielded positive improvements in vocal symptomology in five voice over actors who were trained in VCT. Next steps should include a larger enrollment of voice actors to determine optimal preventative and recovery techniques.

The Effect of Mandarin Vowels on Acoustic Analysis: A Prospective Observational Study

OBJECTIVES

Although vowels are of interest for acoustic analysis in clinics, there is no consensus regarding the effect of vowel selection on acoustic perturbation parameters. This study aimed to reveal the effects of Mandarin vowels on acoustic measurements.

STUDY DESIGN

A prospective observational study.

METHODS

This prospective observational study enrolled normal phonation Mandarin speakers at the Otolaryngology Department of the Eye & ENT Hospital affiliated with Fudan University from December 2020 to August 2021. This study recruited 107 normal-voiced Mandarin speakers (59 women and 49 men) with a median age of 26 (22, 33) years old. The objective measures included traditional acoustic parameters (fundamental frequency, harmonic-to-noise ratio, percent jitter, and percent shimmer) and cepstral analysis (smoothed cepstral peak prominence) of six Mandarin vowels (ɑ /a/, o /o/, e /ɤ/, i /i/, u /u/, ü /y/).

RESULTS

The acoustic analysis revealed no significant differences in the fundamental frequency among vowels. The low vowel /a/ had the highest values for percent jitter and percent shimmer and the lowest harmonic-to-noise ratio value. The back vowel /u/ had the lowest cepstral measures (P < 0.05).

CONCLUSIONS

The acoustic analysis significantly varied across the different Mandarin vowels, and these differences must be considered for the effective clinical application of objective evaluations.

Impact of Face Masks on Speech Acoustics and Vocal Effort in Healthcare Professionals

OBJECTIVES/HYPOTHESIS

We investigated speech acoustics and self-reported vocal symptoms in mask-wearing healthcare professionals. We hypothesized that there would be an attenuation of spectral energies and increase in vocal effort during masked speech compared to unmasked speech.

STUDY DESIGN

Within and between subject quasi-experimental design.

METHODS

We prospectively enrolled 21 healthcare providers (13 cisgender female, 8 cisgender male; M = 32.9 years; SD = 7.9 years) and assessed acoustics and perceptual measures with and without a face mask in place. Measurements included: 1) acoustic Vowel Articulation Index (VAI); 2) cepstral and spectral acoustic measures; 3) traditional vocal measures (e.g., fundamental frequency, intensity); 4) relative fundamental frequency (RFF); and 5) self-reported ratings of vocal effort and dyspnea.

RESULTS

During masked speech, there was a significant reduction in VAI, high-frequency information (>4 kHz), and RFF offset 10, as well as a significant increase in cepstral peak prominence and perceived vocal effort. Further analysis showed that high-frequency attenuation was more pronounced when wearing an N95 mask compared to a simple mask.

CONCLUSIONS

Face masks pose an additional barrier to effective communication that primarily impacts spectral characteristics, vowel space measures, and vocal effort. Future work should evaluate how long-term mask use impacts vocal health and may contribute to vocal problems.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:391-397, 2022.

Quantitative and Qualitative Electroglottographic Wave Shape Differences in Children and Adults Using Voice Map-Based Analysis

Purpose The purpose of this study is to identify the extent to which various measurements of contacting parameters differ between children and adults during habitual range and overlap vocal frequency/intensity, using voice map-based assessment of noninvasive electroglottography (EGG). Method EGG voice maps were analyzed from 26 adults (22-45 years) and 22 children (4-8 years) during connected speech and vowel /a/ over the habitual range and the overlap vocal frequency/intensity from the voice range profile task on the vowel /a/. Mean and standard deviations of contact quotient by integration, normalized contacting speed, quotient of speed by integration, and cycle-rate sample entropy were obtained. Group differences were evaluated using the linear mixed model analysis for the habitual range connected speech and the vowel, whereas analysis of covariance was conducted for the overlap vocal frequency/intensity from the voice range profile task. Presence of a "knee" on the EGG wave shape was determined by visual inspection of the presence of convexity along the decontacting slope of the EGG pulse and the presence of the second derivative zero-crossing. Results The contact quotient by integration, normalized contacting speed, quotient of speed by integration, and cycle-rate sample entropy were significantly different in children compared to (a) adult males for habitual range and (b) adult males and adult females for the overlap vocal frequency/intensity. None of the children had a "knee" on the decontacting slope of the EGG slope. Conclusion EGG parameters of contact quotient by integration, normalized contacting speed, quotient of speed by integration, cycle-rate sample entropy, and absence of a "knee" on the decontacting slope characterize the wave shape differences between children and adults, whereas the normalized contacting speed, quotient of speed by integration, cycle-rate sample entropy, and presence of a "knee" on the downward pulse slope characterize the wave shape differences between adult males and adult females. Supplemental Material https://doi.org/10.23641/asha.15057345.

Effects of Vocal Intensity and Fundamental Frequency on Cepstral Peak Prominence in Patients with Voice Disorders and Vocally Healthy Controls

OBJECTIVE

Cepstrum-based voice measures, such as smoothed cepstral peak prominence (CPPS), are influenced by voice sound pressure level (SPL) in vocally healthy adults. Since it is unclear if similar effects hold in voice disordered adults and how these interact with natural fundamental frequency (fo) changes, this study examines voice SPL and fo effects on CPPS in women with vocal hyperfunction and vocally healthy controls.

STUDY DESIGN

Retrospective matched case-control study.

METHODS

Fifty-eight women with vocal hyperfunction were individually matched with 58 vocally healthy women for occupation and approximate age. The patient group comprised women exhibiting phonotraumatic vocal hyperfunction associated with vocal fold nodules (n = 39) or polyps (n = 5), and nonphonotraumatic vocal hyperfunction associated with primary muscle tension dysphonia (n = 14). All participants sustained the vowel /a/ at soft, comfortable, and loud loudness conditions. Voice SPL, fo, and CPPS (dB) were computed from acoustic voice recordings using Praat. The effects of loudness condition, measured voice SPL, and fo on CPPS were assessed with linear mixed models. Pairwise correlations among voice SPL, fo, and CPPS were assessed using multiple regression analysis.

RESULTS

Increasing voice SPL correlated significantly (P < 0.001) with higher CPPS in both patient (r2 = 0.53) and normative groups (r2 = 0.45). fo had statistically significant effects on CPPS (P < 0.001), but with a weak relation for the patient (r2 = 0.02) and control groups (r2 = 0.05).

CONCLUSIONS

In women with and without voice disorder, CPPS is highly affected by the individual's voice SPL in vowel phonation. Future studies could investigate how these effects should be controlled for to improve the diagnostic value of acoustic-based cepstral measures.

Fundamental Frequency and Jitter Percent in MDVP and PRAAT

PURPOSE

This study initially investigated the relationship between Fundamental Frequency and Jitter Percent across and within MDVP and PRAAT. Subsequently, it explored if the measured acoustic signal's Length or the analysis temporal segment selection impacts potential correlation across the tools' measures.

METHODS

We collected forty-two Maximum Phonation Time acoustic signals from 10 participants with Healthy Voices in a standardized setting. We excluded from enrollment any potential participants having a history of voice disorders or showing an abnormality in a pre-study assessment.

RESULTS

There is no correlation between Jitter percent's values and Fundamental Frequency within either Tool in our healthy voice samples. The Length of the acoustic signal and temporal analysis selection impact the correlation between Jitter Percent measurements across the two tools; The correlation between Fundamental Frequency measurements across the devices was not affected. Means of Fundamental Frequency did not differ across the two devices but show a persistent pattern of greater values in MDVP. Jitter Percent measurements were significantly higher in MDVP CONCLUSIONS: There is a potential for clinicians using PRAAT assessments in the clinic to make inferences from research using MDVP as an analysis tool. Further work is needed in patients with Voice disorders to explore that possibility.

A Nonrandomized Trial for Student Teachers of an In-Person and Telepractice Global Voice Prevention and Therapy Model With Estill Voice Training Assessed by the VoiceEvalU8 App

Purpose This study investigated the effects of the in-person and telepractice Global Voice Prevention and Therapy Model (GVPTM) treatment conditions and a control condition with vocally healthy student teachers. Method In this single-blinded, nonrandomized trial, 82 participants completed all aspects of the study. Estill Voice Training was used as the stimulability component of the GVPTM to train multiple new voices meeting all the vocal needs of the student teachers. Outcomes were assessed using acoustic, perceptual, and aerodynamic measures captured by the VoiceEvalU8 app at pre and post in fall and during student teaching in spring. Results Significant improvements were achieved for several acoustic and perceptual measures in the treatment conditions, but not in the control condition. The in-person and telepractice conditions produced similar results. The all-voiced phrase and connected speech were more successful in demonstrating voice change for some of the perturbation measures as compared to sustained /a/. Conclusions The treatment conditions were successful in improving the participants' voices for fundamental frequency and some acoustic perturbation measures while maintaining the improvements during student teaching. In addition, the treatment conditions were successful in decreasing the negative impact of voice-related quality of life and vocal fatigue during student teaching. Future research should address the effectiveness of the various components of the GVPTM, the application of the GVPTM with patients with voice disorders, the relevance of defining auditory-perceptual terms by the anatomy and physiology of the voice production system (i.e., Estill Voice Training), and the continued use of the VoiceEvalU8 app for clinical voice investigations. Supplemental Material https://doi.org/10.23641/asha.13626824.

Vocal fold oscillation pattern changes related to loudness in patients with vocal fold mass lesions

Introduction

Vocal fold mass lesions can affect vocal fold oscillation patterns and therefore voice production. It has been previously observed that perturbation values from audio signals were lower with increased loudness. However, how much the oscillation patterns change with gradual alteration of loudness is not yet fully understood.

Material and methods

Eight patients with vocal fold mass lesions were asked to perform a glide from minimum to maximum loudness on the vowel /i/, ƒ_o of 125 Hz for male or 250 Hz for female voices. During phonation the subjects were simultaneously recorded with transnasal high speed videoendoscopy (HSV, 20,000 fps), electroglottography (EGG), and an audio recording. Based on the HSV material the Glottal Area Waveform (GAW) was segmented and GAW parameters were computed.

Results

The greatest vocal fold irregularities were observed at different values between minimum and maximum sound pressure level. There was a relevant discrepancy between the HSV and EGG derived open quotients. Furthermore, the EGG derived sample entropy and GAW values also evidenced different behavior.

Conclusions

The amount of vocal fold irregularity changes with varying loudness. Therefore, any evaluation of the voice should be performed under different loudness conditions. The discrepancy between EGG and GAW values appears to be much stronger in patients with vocal fold mass lesions than those with normal physiological conditions.

Level of evidence

4.

Application of High Speed Digital Imaging (HSDI) technique and voice acoustic analysis in the diagnosis of the clinical form of Presbyphonia in women

&lt;b&gt;Introduction:&lt;/b&gt; The aging process of voice begins after the age of 60 and has an individually variable course. Voice quality disorders at this age are called senile voice (Presbyphonia or Vox Senium). Voice pathology is particularly severe in women. The aim of the study was to diagnose the clinical form of Presbyphonia in elderly women using High Speed Digital Imaging (HSDI) and acoustic voice analysis. &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt; Study included 50 elderly women (average age 69) with dysphonia (Group I). Control group (Group II) included 30 women (average age 71) without voice quality disorders. Visualization assessment has been conducted with High Speed Digital Imaging (HSDI) with High Speed camera (HS). Acoustic evaluation of voice included analysis isolated vowel "a" and continuous linguistic text with Diagnoscope Specialista software. Maximum Phonation Time (MPT) has been determined. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; In Group I, 78% of women revealed vocal folds vibrations asymmetry, vibration amplitude increase, Mucousal Wave (MW) limitation and Type D glottal insufficiency (GTs). Acoustic voice analysis proved decrease in F0, increase in Jitter, Shimmer, NHR. In 22% of women, next to vibrations asymmetry, vibration amplitude reduction and MW limitation, Type E glottal insufficiency (GTs) have been found. Acoustic voice analysis revealed slight decrease in F0 and the presence of numerous non-harmonic components in the glottis region. &lt;br&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Vocal folds visualization with HSDI showed edema, less often atrophy in elderly women. Both forms of dysphonia were caused abnormal values of F0, Jitter, Shimmer, NHR in the acoustic voice evaluation and significant reduction of MPT.

Multiparameter Voice Assessment in Dysphonics: Correlation Between Objective and Perceptual Parameters

BACKGROUND

Perceptual assessment and objective measures of voice provide a quantifiable tool for determining the degree of glottal closure, thus helping to distinguish dysphonic voices from normal voices. The correlation between the perceptual and objective parameters of voice in dysphonic can enable the voice pathologist to be more effective in differentiating the normal voices from dysphonic voices. However, only a few studies have investigated the correlation between these measures.

OBJECTIVE

To document the differences in the perceptual and objective parameters of voice in participants with dysphonia and normal controls and to investigate the correlation between the perceptual and objective parameters of voice among participants with dysphonia.

STUDY DESIGN

This investigation deployed standard group comparison and a retrospective study.

METHODS

Two groups of participants were included in the study. Participants in group 1 were diagnosed as having a voice disorder secondary to organic pathologies and group 2 participants had a clinically normal voice. Phonation samples of all the participants were collected and perceptual analysis was carried out using the GRBAS rating scale. As part of the objective measures, acoustic and cepstral measures were extracted from the phonation samples.

RESULTS

The analysis of the results revealed significant differences in perceptual ratings between the normal (control) and dysphonic groups. The mean values of all the objective measures of voice presented significant differences between participants of both groups. The perceptual ratings of grade, breathiness, and roughness showed better correlations with the cepstral measures than with the time-based acoustic measures.

CONCLUSIONS

Further foraging research on the correlation between perceptual and objective measures of voice in various degrees of dysphonia will improve reliability while discriminating and quantifying hoarse, harsh and breathy voices from modal voices.

Effects of Fundamental Frequency, Vocal Intensity, Sample Duration, and Vowel Context in Cepstral and Spectral Measures of Dysphonic Voices

Purpose Smoothed cepstral peak prominence (CPPS) and harmonics-to-noise ratio (HNR) are acoustic measures related to the periodicity, harmonicity, and noise components of an acoustic signal. To date, there is little evidence about the advantages of CPPS over HNR in voice diagnostics. Recent studies indicate that voice fundamental frequency (F0) and intensity (sound pressure level [SPL]), sample duration (DUR), vowel context (speech vs. sustained phonation), and syllable stress (SS) may influence CPPS and HNR results. The scope of this work was to investigate the effects of voice F0 and SPL, DUR, SS, and token on CPPS and HNR in dysphonic voices. Method In this retrospective study, 27 Brazilian Portuguese speakers with voice disorders were investigated. Recordings of sustained vowels (SVs) /a:/ and manually extracted vowels (EVs) /a/ from Consensus Auditory-Perceptual Evaluation of Voice sentences were acoustically analyzed with the Praat program. Results There was a highly significant effect of F0, SPL, and DUR on both CPPS and HNR (p < .001), whereas SS and vowel context significantly affected CPPS only (p < .05). Higher SPL, F0, and lower DUR were related to higher CPPS and HNR. SVs moderately-to-highly correlated with EVs for CPPS, whereas HNR had few and moderate correlations. In addition, CPPS and HNR highly correlated in SVs and seven EVs (p < .05). Conclusion Speaking prosodic variations of F0, SPL, and DUR influenced both CPPS and HNR measures and led to acoustic differences between sustained and excised vowels, especially in CPPS. Vowel context, prosodic factors, and token type should be controlled for in clinical acoustic voice assessment.

Classificação espectrográfica do sinal vocal: relação com o diagnóstico laríngeo e a análise perceptivo-auditiva

RESUMO Objetivo Verificar se existe associação entre a presença de alteração laríngea, a análise perceptivo-auditiva da qualidade vocal e a classificação espectrográfica do sinal vocal em indivíduos com distúrbio de voz. Métodos Participaram 478 pacientes com distúrbios de voz. Foi realizada gravação da vogal /Ɛ/ sustentada e o exame médico para estabelecimento de diagnóstico laríngeo. Os espectrogramas da vogal foram utilizados para classificação dos sinais em Tipo I, II, III e IV. Resultados Vozes de indivíduos sem alteração laríngea foram classificadas, predominantemente, como Tipo I e Tipo II, enquanto sinais de indivíduos com alteração laríngea foram classificados nos Tipos III e IV. Vozes desviadas foram classificadas, predominantemente, como Tipo II, enquanto os sinais de pacientes com desvio vocal foram categorizados, predominantemente, como Tipos II e III. Apenas os sinais de indivíduos com desvio vocal foram classificados como Tipo IV. Sinais Tipo III e IV apresentaram valores mais elevados no grau geral do desvio e nos graus de rugosidade e soprosidade, em relação aos sinais Tipo I e Tipo II. Os sinais Tipo IV apresentaram maior grau geral e graus de rugosidade e soprosidade, em comparação aos sinais Tipo III. Apenas os sinais Tipo IV apresentaram valores mais elevados no grau de tensão, em relação aos sinais Tipo I, II e III. Conclusão Há associação entre a presença de alteração laríngea, a análise perceptivo-auditiva e a classificação espectrográfica do sinal vocal em indivíduos com distúrbio de voz.

Fundamental Frequency and Intensity Effects on Cepstral Measures in Vowels from Connected Speech of Speakers with Voice Disorders

OBJECTIVE

Cepstral peak prominence (CPP) and smoothed CPP (CPPS) have been described as reliable parameters to detect overall dysphonia in standardized connected speech samples. Recent studies indicate that vocal intensity (sound pressure level, SPL) and fundamental frequency (f_o) changes may influence cepstral measurement results in healthy speakers. The main aim of the present work was to investigate the effects of prosody related SPL and f_o variations on cepstral measures in speech of adults with voice disorders.

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

Recordings of CAPE-V sentences from 27 voice disordered Brazilian Portuguese speakers (19 women, eight men) with a mean age of 45 years (SD = 13) were investigated. Five /a/ vowels were manually extracted from stressed syllables in different positions. Voice f_o (Hz), SPL (dBA), CPP (dB), and CPPS (dB) were computed using PRAAT. Statistical analysis included Linear Mixed Models with ANCOVA and Bonferroni post hoc tests.

RESULTS

Voice SPL as single factor and combined with f_o had a highly significant effect (P ≤ 0.001), while f_o alone had no significant impact on both CPP and CPPS (P ≥ 0.77). Voice f_o, SPL, CPP, and CPPS of the first vowel were all significantly lower than of the last vowel (P ≤ 0.03).

CONCLUSION

In vowel samples from connected speech of adults with voice disorders, we observed better CPP and CPPS in higher voice SPL alone and combined with higher f_o. Further, the vowel position influenced the present results. A larger clinical study should confirm how prosody related SPL and f_o and vowel position effects could be controlled for in connected speech samples.

Acoustic Voice Quality Index as a Potential Tool for Voice Screening

INTRODUCTION

To diminish the risk of voice disorders in people who are highly dependent on their voices, such as teachers, vocal screening is important already at the beginning of such individuals' professional studies. A reliable, specified screening tool is needed. The Acoustic Voice Quality Index (AVQI) has been found to differentiate normal voices from abnormal voices and to serve as a treatment outcome measure. This study investigated whether AVQI could be a screening tool in combination with auditory- and self-perception of the voice to discriminate normal from slightly poor voices.

TYPE OF STUDY

Experimental.

METHODS

Some 128 female teaching students (mean age 26.39 years, SD 9.80 years) with no diagnosed voice disorders participated in this study. They read aloud a text in Finnish, sustained the vowel /a:/, and filled the Voice Handicap Index (VHI) questionnaire. Voice samples were recorded with an AKG C544L headset microphone, iFocusrite soundcard, and Praat software using a 44100 sample rate and 16-bit amplitude quantization. Five expert voice therapists evaluated the samples to determine the grade of dysphonia (G) using a scale of 0-0.5 (=normal), 0.5-1 (=mild), 1-2 (=moderate), and 2-3 (=severe). Three medial seconds of [a:] and the first 31 syllables of the text were analyzed using AVQI script version 03.01 in Praat (5.3.55). The analysis gives one AVQI score per participant (scale 0-10). The AVQI threshold of normal and disordered voices for Finnish speakers is 1.83; a G_mean = 0.0-0.5 and VHI score <19 were considered normal. Statistical analysis was done using the receiver operating characteristic (ROC) curve, Spearman's correlation coefficient, and the independent samples t test.

RESULTS

According to the AVQI results, the area under the curve (A_ROC) was 0.554, which is fair. The Youden index gave a cutoff value of 0.30 with a sensitivity of 85% and a specificity of 81.1%. There were weak but significant correlations between G_mean and AVQI and two AVQI parameters, smoothed cepstral peak prominence and harmonic-to-noise ratio (r = 0.27; --0.24; -0.20, respectively; |P < 0.05); and between total VHI and AVQI score and cepstral peak prominence (r = 0.21; 0.20, respectively; P < 0.05). Furthermore, the AVQI scores differed significantly between the groups with a VHI total score <19 and ≥19.

CONCLUSIONS

AVQI did not differentiate between voices that had been perceptually judged as normal or slightly abnormal, but a combination of perceptual assessment in the form of AVQI and VHI could better screen slightly deviant voices.

Immediate Lip Trill Effects on the Standard Diagnostic Measures Voice Range Profile, Jitter, Maximum Phonation Time, and Dysphonia Severity Index

OBJECTIVES

Semi-occluded vocal tract exercises are widely applied to improve vocal performance in speakers, singers, and voice patients. This study investigates immediate lip trill effects on standard voice assessment measures including voice range profiles, jitter, maximum phonation time, and Dysphonia Severity Index in vocally healthy women.

STUDY DESIGN

Experimental study.

SETTING

Otolaryngology clinic within tertiary hospital.

SUBJECTS AND METHODS

Twenty-five vocally healthy women between 19 and 58 years (mean 38.4) were assessed before and after 3 minutes of standardized lip trill training combined with defined voice fundamental frequency and intensity modulations. Main outcome measures were fundamental frequency (F₀) during counting (F₀ counting), the singing voice range profile parameters minimum, maximum and range of F₀ and voice sound pressure level (voice SPL), jitter (%), maximum phonation time (MPT), and the Dysphonia Severity Index (DSI). Wilcoxon signed rank test was applied to determine significant changes after exercise.

RESULTS

After exercise the singing F₀ and SPL range significantly increased from 549 (SD 217) to 612 (238) Hz and 45.1 (10.1) to 47.3 (9.8) dBA, resepctively (P<0.05). Maximum voice SPL significantly increased from 90.9 (10.3) to 94 (9.7) dBA (P<0.05). Mean F₀ during counting showed a highly significant increase from 198 (SD 25.6) to 209 Hz (SD 25.4, P<0.01). No significant changes were found for all other parameters.

CONCLUSIONS

In vocally healthy women, lip trill training immediately facilitates increases in mean F₀ during counting, and singing F₀ and SPL range. Future studies should investigate, if changes to these parameters indicate immediate responsiveness to voice exercise also in voice patients, and if these findings transfer to long-term effects through prolonged training.

Relationship Between Laryngeal Signs and Symptoms, Acoustic Measures, and Quality of Life in Finnish Primary and Kindergarten School Teachers

OBJECTIVE

This study investigated the relationship between the acoustic measure smoothed cepstral peak prominence (CPPS), teacher's quality of life as measured by the voice activity and participation profile (VAPP), laryngeal signs and symptoms, voice related health problems and laryngoscopic findings in Finnish teachers. The relationship between CPPS and sound pressure level (SPL) was also assessed.

METHODS

Vowel and text samples from 183 healthy Finnish teachers (99 kindergarten teachers [KT] and 84 primary school teachers [PST]) were analyzed for CPPS. Text reading was recorded in conversational loudness by PST, and KT were recorded wearing headphones, while listening to a masking noise of children talking to simulate their classroom voice and environment. CPPS values were correlated with the VAPP, self-reported laryngeal signs and symptoms, voice related health variables, and laryngoscopic findings.

RESULTS

There was a significant difference between the two groups for CPPS text, PST showed significantly lower CPPS values (10.44) than KT (11.52). There was no difference between the two groups for CPPS vowel phonation. There was a significant correlation between SPL text and CPPS text for KT (P < 0.001, r = 0.43) but not for PST (P < 0.10, r = 0.16). There was a significant correlation between SPL vowel and CPPS vowel for both PST (P < 0.001, r = 0.47) and KT (P < 0.001, r = 0.45). CPPS did not correlate with the VAPP, laryngeal signs and symptoms, health variables or laryngeal findings. Factorial analysis of variance resulted in a significant relationship between the VAPP, laryngeal signs and symptoms, and teacher type. Teacher type and symptoms had a significant effect on VAPP scores.

CONCLUSIONS

In the present work CPPS does not correlate with vocal health indicators of functionally healthy teachers. CPPS was significantly influenced by differences in speaking voice SPL, emphasizing the impact of recording conditions and technique. There was a significant relationship between laryngeal signs and symptoms, teacher type and the VAPP. Laryngeal signs and symptoms and teacher type are important variables and should be included in the clinical evaluation of occupational voice users, and voice problems.

Vocal characteristics of 5-year-old children: proposed normative values based on a French-speaking population†

Purpose: Previous research proposed normative data on gender- and age-specific voice acoustics for adults. Such reference values are lacking for children, particularly under the age of 6. This study was intended (1) to collect reliable normative data for the acoustic parameters of 5-year-old children's voices, and (2) to investigate potential gender-specific differences.Study: Prospective and cross-sectional.Methods: Acoustic analyses were done on the voices of 53 normophonic children (26 girls; 27 boys) aged 5;0-5;11 years, using Praat software. The fundamental frequency, local jitter, local shimmer, and noise-to-harmonics ratio (NHR) were measured on the sustained vowels [a], [i], and [u]. The highest frequency, lowest frequency, and frequency range were measured using ascending and descending glissandi on the vowel [a].Results: For the three sustained vowels, the mean fundamental frequency ranged from 255 Hz to 277 Hz, mean jitter ranged from 0.394% to 0.591%, mean shimmer ranged from 2.571% to 5.824%, and mean NHR ranged from 0.009 to 0.034. The frequency range was from 190 Hz to 750 Hz, which corresponds to 23.7 semitones. No gender difference was found, except for NHR on the vowel [a].Conclusions: The lack of gender differences - other than for NHR on the vowel [a] - led us to propose mixed norms for 5-year-old boys and girls combined.Implications: These normative data will allow clinicians to compare children's voice assessments to specific references in order to enhance diagnostic accuracy and measure therapy outcomes.

Feature Maps of the Acoustic Spectrum of the Voice

The change in the spectrum of sustained /a/ vowels was mapped over the voice range from low to high fundamental frequency and low to high sound pressure level (SPL), in the form of the so-called voice range profile (VRP). In each interval of one semitone and one decibel, narrowband spectra were averaged both within and across subjects. The subjects were groups of 7 male and 12 female singing students, as well as a group of 16 untrained female voices. For each individual and also for each group, pairs of VRP recordings were made, with stringent separation of the modal/chest and falsetto/head registers. Maps are presented of eight scalar metrics, each of which was chosen to quantify a particular feature of the voice spectrum, over fundamental frequency and SPL. Metrics 1 and 2 chart the role of the fundamental in relation to the rest of the spectrum. Metrics 3 and 4 are used to explore the role of resonances in relation to SPL. Metrics 5 and 6 address the distribution of high frequency energy, while metrics 7 and 8 seek to describe the distribution of energy at the low end of the voice spectrum. Several examples are observed of phenomena that are difficult to predict from linear source-filter theory, and of the voice source being less uniform over the voice range than is conventionally assumed. These include a high-frequency band-limiting at high SPL and an unexpected persistence of the second harmonic at low SPL. The two voice registers give rise to clearly different maps. Only a few effects of training were observed, in the low frequency end below 2 kHz. The results are of potential interest in voice analysis, voice synthesis and for new insights into the voice production mechanism.