Vocal stability in functional dysphonic versus healthy voices at different times of voice loading

Acoustic and Physiological Voice Assessment And Maximum Phonation Time In Patients With Different Types Of Dysarthria

OBJECTIVE

To compare the maximum phonation time of /a/, acoustic glottal source parameters, and physiological measures in patients with dysarthria.

METHOD

Thirteen patients were classified according to dysarthria type and divided into functional profiles (hypofunctional, hyperfunctional, and mixed). Assessments of maximum phonation time of /a/, glottal source parameters, electroglottography, and nasometry were performed. Results were compared between groups using ANOVA and Tukey posthoc tests.

RESULTS

The highest fundamental frequency differed significantly between groups, with the hyperfunctional profile showing higher values than the other participant groups. Reductions in the maximum phonation time of /a/ and alterations in acoustic glottal source parameters and electroglottography measures were observed in all groups, with no significant differences between them. The remaining measures did not differ between groups.

CONCLUSION

The maximum phonation times for /a/ were reduced in all participant groups, suggesting air escape during phonation. The presence of alterations in several glottal source parameters in all participant groups is indicative of noise, tremor, and vocal instability. Lastly, the high fundamental frequency in patients with a hyperfunctional profile reinforces the presence of vocal instability. These findings suggest that, although the characteristics observed in the assessments were consistent with expectations of patients with dysarthria, it is difficult to perform a differential diagnosis of this condition based on acoustic and physiological parameters alone.

Immediate Effects of Straw Phonation in Water Exercises on Parameters of Vocal Loading in Carnatic Classical Singers

OBJECTIVE

The present study aimed to investigate the effect of vocal loading and the immediate effects of straw phonation in water exercises on parameters of vocal loading in Carnatic classical singers.

STUDY DESIGN

A within-subject pretest-posttest design.

METHODS

Twelve healthy Carnatic classical singers participated in the vocal loading experiment for 2 days, referred to as no-treatment and treatment conditions. The vocal loading task consisted of 1 hour of continuous singing in the presence of background noise. For the treatment condition, the participants followed a 10-minute straw phonation in water exercises before the vocal loading task. Acoustic, electroglottographic, and self-rated perceptual voice measures were recorded before and after the vocal loading task on both days.

RESULTS

Pretest and posttest comparison of various outcome measures during no-treatment day suggested a significant increase in shimmer percent, decrease in maximum phonation duration of vowel /a/, and increase in perceived phonatory effort, perceived vocal effort, and Evaluation of Ability to Sing Easily scores. Pretest and posttest comparisons during treatment day showed a significant increase in Mean F0, Highest F0, and Lowest F0, perceived phonatory effort, and perceived vocal effort scores. However, changes in Mean F0, Highest F0, and Lowest F0 measures were small in the posttest condition compared to pretest.

CONCLUSION

The present results suggest that vocal loading did induce changes in Carnatic classical singers' voices. However, there is no substantial evidence that straw phonation is effective in reducing the vocal loading in Carnatic classical singers. Further studies are required to corroborate the current findings.

The Impact of a Vocal Loading Task on Voice Characteristics of Female Speakers With Benign Vocal Fold Lesions

OBJECTIVES

To examine the effect of a vocal loading task on measures of vocal structure and function in females with benign vocal fold lesions (BVFLs) and determine if change is observed in voice and lesion characteristics.

STUDY DESIGN

Prospective cohort study.

METHODS

Twenty-eight (n = 28) female subjects with phonotraumatic BVFLs completed a vocal loading task of 30 minutes of reading aloud at 75-85 dBA. Multidimensional voice evaluation was completed pre- and post-load, including audio and videostroboscopy recordings and images for expert perceptual ratings and acoustic and aerodynamic evaluation. Subjects also scored themselves using a 10 cm visual analogue scale for Perceived Phonatory Effort, and completed the Evaluation of Ability to Voice Easily, a 12 item self-report scale of current perceived speaking voice function. An exploratory rather than confirmatory approach to data analysis was adopted. The direction and magnitude of the change scores (pre- to post-load) for each individual, across a wide variety of instrumental and self-report measures, were assessed against a Minimal Clinically Important Difference criteria.

RESULTS

Observations of change and the direction of change in vocal response of individuals with BVFLs to 30 minutes of loud vocal load was variable. Minimal to no change was noted for participants pre- to post-load as rated perceptually, for auditory and videostroboscopy samples. For most instrumental measures, change was shown for many participants including an overall improvement in aerodynamic and acoustic measures of function and efficiency post-load for 20 participants (77%) and decline in function for 4 participants (15%). Self-reported effort and vocal function post-load was multidirectional with similar numbers of participants reporting no change, improved function or a decline.

CONCLUSION

Subjects with BVFLs demonstrate change in vocal function following 30 minutes of vocal load. While this change can be variable and multidirectional, overall improvement was observed in instrumental measures of function and efficiency for most participants. Some participants perceived this change to be an increase in effort, some a reduction in effort and some perceived no change. Improved vocal function despite relative lesion stability can seemingly occur after loading in some pathological voices.

Acoustic, Perceptual, and Laryngoscopic Changes Post Vocal Abuse at a College Fest

INTRODUCTION

College students use their voices at excessively loud intensities and long durations during college fests. The accumulative effect of vocally abusive behaviors in the presence of high ambient noise, poor vocal hygiene, and other environmental factors contribute significantly towards reducing vocal effectiveness in college students.

OBJECTIVE

The present study aimed to study the effect of a vocally demanding situation (college Fest) on perceptual and objective voice features of college students.

METHODOLOGY

In this study, a total number of 27 undergraduate female students participated in the age range of 18-27 years. Pre-test-post-test research design was applied. Data analysis consisted of video stroboscopic examination, acoustic analysis using the Multi-dimensional voice program (MDVP), and perceptual evaluation with the GRBAS scale. The data obtained were processed using descriptive statistics and non-parametric tests to determine the difference in each measured parameter pre- and postfest.

RESULTS AND DISCUSSION

Incomplete glottis closure, asymmetric vibration of vocal folds, and aperiodicity of vocal folds increased significantly postcollege Fest. GRBAS parameters also showed a change from pre Fest scores on grade (hoarseness) increased by 38%, breathiness in 34%, roughness in 26%, Asthenia in 15%, and strain increased in 38% participants. A P-value estimation revealed significantly higher scores in Jitter percent, Shimmer percent, and relative average perturbation than pre-fest scores.

CONCLUSION

The results of the present study indicate a high risk of vocal disorders among college students post Fest. This study suggests a potential unmet need for college students to receive education before cultural events on optimal vocal usage, vocal hygiene, and an appropriate period of vocal rest.

Vocal resistance among choir singers

PURPOSE

The purpose of the present study was to compare the voice of choir singers before and after 60 min of singing and after an absolute rest.

METHODS

Twenty-one female choir singers aged on average 26.59 years, with experience in choir singing of at least one year were instructed to emit the vowel /a/ before and after singing and after a vocal rest of 30 min for an analysis of acoustic measures, and for the evaluation of their tactile-kinesthetic self-perception. Vocal warm-up was performed for 10 min. The participants were instructed to sing the "Ave Verum" music continuously for 60 min.

RESULTS

f0 (p = 0.0001) and Flo (p = 0.0002) increased after the singing test and were reduced after the vocal rest, in contrast to Fhi (p = 0.001), which continued to be increased compared to the pre-test measure even after the vocal rest. The vAm parameter (p = 0.05) was reduced after continuous singing and rest. All self-evaluation symptoms increased after the continuous singing task and were reduced after the 30 min rest, except for complaints of low voice, pain when swallowing and cough/throat clearing.

CONCLUSION

60 min of continuous use of the singing voice induced signs of vocal fatigue with an increase in f0, with improvement of symptoms and a reduction of f0 occurring after 30 min of vocal rest.

Long term phonatory function following acoustic neuroma surgery: a cohort study

Background: Acoustic neuroma (AN) is a well-recognized cause of neurological morbidity, peripheral facial paralysis being one of the most prevalent. Phonatory dysfunction in the late post-operative term has not been properly addressed so far.Objective: The objective of this study is to describe the outcomes of phonatory function on the long-term follow-up of AN surgery and identify its prognostic factors.Material and methods: This cohort study included patients submitted to AN surgery from 1999 to 2014, with a mean follow up of 6.4 ± 4.5 years. To evaluate the phonatory function, we performed a combination of noninvasive acoustic and aerodynamic measurements including vocal intensity and stability, maximum declination rate of the glottal airflow (MDR) and transglottal pressure scale (TP).Results: 101 patients were studied. 25 (24.7%) presented a deficit in phonatory function. Women comprised 56% and the mean age was 42.4 ± 13.8 years (range19-80). 100% presented reduced expiratory airflow capacity with excessive manifestation of the laryngeal musculature (TP > 1,23s ;MDR/z/<MDR/s/). Dysphonic patients presented more neurofibromatosis II (NF II) (40% vs 12.7% p = .002), large tumors (3.8 ± 1.1 p = .002) and needed less surgeries (≥256.7% vs 74.6%, p = .0073) in univariate analysis. NFII and tumor size were predictive of dysphonia according to multivariate analysis (NFII-OR 5.57, p = .006; tumor size-each 1 cm, OR1.68, p = .062).Conclusion: The late postoperative prevalence of dysphonia corresponded to 24.7%. Dysphonia could be secondary to the hyperfunction of laryngeal musculature explained by the reduced expiratory airflow found in our patients. Tumor size and NF II were predictors for the occurrence of dysphonia in the present study.HighlightsThe comprise of phonation function can be a morbidity of AN surgeryNF II and tumor size were predictive of dysphonia on late postoperative periodData of hypofunction secondary to the phonatory hyperfunction were unanimous in the dysphonic patients.The early diagnosis and treatment of phonation function could avoid alterations of pneumophono-articulatory coordination and projection deficiency.

Which Sung Pitch Range is Best for Boys During Voice Change?

The question of how and what boys should sing during adolescent voice change has challenged educators and choir leaders for the last century. As the larynx enlarges during adolescence, most boys will follow the descending pitch of their speaking voice and move to singing vocal parts with a lower pitch range. Occasionally a boy may continue to sing in his treble (soprano) range while his larynx is growing and his speaking pitch is lowering. There is much opinion on the wisdom of such practices, but until now there has been no quantifiable evidence to illustrate the discussion. The established historic and cultural practices can now be reassessed in the light of quantitative analyses of vocal function. This longitudinal case study used electroglottographic measures from one boy over a 3-year period to investigate the efficiency of vocal fold adductory behavior in both prechange and midchange singing. In the first recording, he is aged 10 years old and has an unchanged voice. In the second recording, he is aged 13 years old and has a speaking voice in the Cooksey Stage III of voice change. Up to and including the time of the second recording, he had chosen to remain singing exclusively in his treble (soprano) range. The comparison between the two recordings of the observed regularity and efficiency of vocal fold adduction suggests that singing in this pitch range has become less healthy and effective; this is also represented in the overall perceived vocal comfort levels heard in the recordings. The implications for educators are that the longitudinal development of singing habits will be enhanced for boys who move to singing with their new baritone range as their larynx grows, rather than remaining in a treble range.

Mucosal wave measurements in the diagnosis of functional dysphonia

ntroduction: The publication describes the characteristics of the glottis in FDs objectified by OQ, measured with VSK and EGG.

AIM

The aim of the study was to objectify glottal function in different types of FDs. The scope was to use open quotients gained from various mucosal wave imaging techniques for differential diagnosis of FDs.

MATERIAL AND METHOD

The study included 204 individuals. In the study, each patient underwent otolaryngological and phoniatric examination. LVS, EGG and VSK were conducted, their results were recorded and stored using an EndoSTROB-DX- -Xion GmbH (Berlin) device with DIVAS software.

RESULTS

All patients with FDs had abnormalities in LVS. A statistical analysis showed differences in LVS characteristics according to the type of FD. The mean value of OQVSK was 0.521 in the control group and 0.565 in the study group (P &lt; 0.05). Significant differences were found between patients with hypofunctional - 0.584 and hyperfunctional dysphonia - 0.55. The QOQEGG mean value in patients with FDs was 0.581 and in the control group 0.549 (P &lt; 0.01). There were statistically significant differences between groups of patients with hyper- and hypofunctional dysphonias. Medians amounted to 0.574 and 0.604, respectively. Authors observed different relations of OQ with the type of FD. They decided to introduce a new parameter, illustrating the proportion of QOQEGG/OQVSK.

CONCLUSIONS

Videostrobokymographic and electroglottographic open quotients differentiate euphony from dysphony. The value of OQVSK and QOQEGG and their proportion varies depending on different types of functional dysphonias. The OQVSK and QOQEGG should be included in the diagnostic algorithm of voice.

Electroglottography in the diagnosis of functional dysphonia

INTRODUCTION

Electroglottography (EGG) is the most commonly used method of indirect visual examination of vocal fold vibration.

AIM

The study was conducted with an aim of assessing EGG quasi open quotient (QOQ_EGG) in different functional dysphonias to develop a differential diagnosis. The second aim was to check the influence of articulation on QOQ_EGG values.

MATERIAL AND METHODS

There were 20 people without voice problems, 20 patients with hypofunctional dysphonia and 20 patients with hyperfunctional dysphonia included in the study. Electroglottography was recorded during comfortable sustained phonation of [a], [e], [i], [o], [u].

RESULTS

There were no statistically significant differences in QOQ_EGG observed during phonation of different vowels in the control group and patients with hyperfunctional dysphonia. In patients with hypofunctional dysphonia, significantly higher values of QOQ_EGG were observed during [a] and [e]. Both in the control and in studied groups vowel [i] was vocalized significantly quieter.

CONCLUSIONS

To conclude, EGG can be useful in differential diagnosis of functional dysphonia. QOQ_EGG is a parameter differentiating hypofunctional dysphonia from hyperfunctional dysphonia. Dissimilarities in articulation of different vowels in patients with various types of dysphonia influence values of QOQ_EGG. EGG study protocol in cases of functional dysphonia should include a comparison of [a], [e], [i] vowels.

Objective measurement of mucosal wave parameters in diagnosing benign lesions of the vocal folds

INTRODUCTION

The diagnostic procedure of phonation is dominated by subjective assessment tools. It seems reasonable to seek methods of quantitative glottal cycle assessment.

OBJECTIVE

The aim of our study was the analysis of open quotients (OQ) of the glottis.

METHODS

One hundred and twenty-four people were included in the study. Methodology was based on tools available in everyday phoniatrics practice - laryngovideostroboscopy (LVS) and electroglottography (EGG). There were statistically significant differences between control and studied group. Vocal fold polyps, nodules and edema influence glottal function in a different manner, what can be illustrated by objective glottal function parameters. Establishing Videostroboscopic Open Quotient values from three parts of glottis and Electroglottographic Quasi Open Quotient (QOQ) value, can help in dividing patients with benign lesions of vocal folds according to the type of disease.

RESULTS AND CONCLUSIONS

Measurement of the open quotient from three parts of the glottis helps to differentially diagnose and localize glottal vocal fold lesions. Videostroboscopic Open Quotient and Electroglottographic QOQ values can be used to quantify the glottal cycle. Videostroboscopic Open Quotient, Electroglottographic QOQ and their ratio varies depending on the type of organic dysphonia.

The Effect of a Vocal Loading Test on Cough and Phonation in Patients With Chronic Cough

OBJECTIVE/HYPOTHESIS

Talking is a significant trigger for cough in patients with chronic cough; however, the stimulus required to trigger cough has not been quantified. The aim of this study was to examine the effect of a vocal loading task on phonation and cough behavior in patients with chronic cough and identify change following therapy.

STUDY DESIGN

This is a prospective observational study.

METHODS

This study involved 33 patients with chronic cough. Participants were assessed with the lingWAVES Vocal Loading Test protocol before and after intervention for chronic cough.

RESULTS

At baseline, almost 40% of patients had impaired vocal function and were unable to complete the vocal loading test. This improved following therapy, with 94% of patients being able to complete the test at follow-up. There was difficulty maintaining phonation, with 60% of the task unvoiced at baseline. This improved following therapy. The vocal loading test triggered coughing in 58% of patients; however, this improved following intervention. Acoustic measures during the vocal loading test did not change following therapy.

CONCLUSION

Phonation is an important trigger for cough. Patients with chronic cough demonstrated impaired performance on tests of vocal loading. Most parameters improved following therapy.

Classroom Noise and Teachers' Voice Production

PURPOSE

The aim of this study was to research the associations between noise (ambient and activity noise) and objective metrics of teachers' voices in real working environments (i.e., classrooms).

METHOD

Thirty-two female and 8 male teachers from 14 elementary schools were randomly selected for the study. Ambient noise was measured during breaks in unoccupied classrooms and, likewise, the noise caused by pupils' activity during lessons. Voice samples were recorded before and after a working day. Voice variables measured were sound pressure level (voice SPL), fundamental frequency, jitter, shimmer, and the tilt of the sound spectrum slope (alpha ratio).

RESULTS

The ambient noise correlated most often with the fundamental frequency of men and voice SPL, whereas activity noise correlated with the alpha ratio and perturbation values. Teachers working in louder ambient noise spoke more loudly before work than those working in lower noise levels. Voice variables generally changed less during work among teachers working in loud activity noise than among those working in lower noise levels.

CONCLUSIONS

Ambient and activity noises affect teachers' voice use. Under loud ambient noise teachers seem to speak habitually loudly, and under loud activity noise teachers' ability to react to loading deteriorates.

Does Cervical Muscular Contraction Affect the Measurement for Electroglottographic Perturbation Parameters?

OBJECTIVES

The purpose was to assess whether cervical muscular contraction during phonation influences the period and amplitude perturbation quotients (PPQ and APQ, respectively) of electroglottographic (EGG) signals, and whether high-pass filtering can attenuate these effects.

STUDY DESIGN

Prospective.

METHODS

We included 19 nondysphonic speakers and 21 patients with muscle tension dysphonia. During the recording of acoustic and EGG signals, each participant was instructed to naturally phonate sustained vowels /i:/ and /a:/ (NP tasks), and additionally, each nondysphonic participant was asked to phonate the same vowels in a nondysphonic voice quality while contracting the cervical muscles (muscular contracted phonation [MCP] tasks). To confirm the contraction, surface and needle electromyography (EMG) was performed. The EGG signals were high-pass filtered at different cutoff frequencies from 0 to 90 Hz and were subsequently analyzed for the PPQ and APQ.

RESULTS

Compared with the NP tasks, the MCP tasks enhanced the cervical EMG activities ranging from 0 to more than 1000 Hz, but conferred only low-frequency noise to the EGG signals under 50 Hz and increased the values for EGG-APQ, but not EGG-PPQ. These EGG-APQ values exhibited gradual decreases after high-pass filtering with an increase in the cutoff frequency ranging from 0 to 50 Hz in both groups, followed by plateaus during the MCP tasks in the nondysphonic group.

CONCLUSIONS

The present results demonstrate that cervical muscular contraction seriously affects the EGG-APQ values for unfiltered EGG signals independent of the EMG activities and that appropriate high-pass filtering over 50 Hz can attenuate these effects.

Objectification of the severity of Reinke's edema

According to the severity, Reinke's edema (RE) of the vocal folds can be divided into three stages as classified by Yonekawa. We evaluated open and closed quotients of vocal folds vibratory cycles using Videostrobokymography (VSK) in a cohort of patients with RE. Parameters were measured from the anterior, medial and posterior third of the vocal folds. Mean values from RE group were OQ (0.44; 0.46; 0.52); CQ (0.56; 0.54; 0.48). Results from the whole glottis OQ and CQ in RE were: OQ=0.48 and CQ=0.52. Significant differences were found for OQ and CQ mean values as well as values measured from each third of the glottis between the control group and patients with RE. In the first Yonekawa group no statistically significant differences were found compared to the control group, but there were significant differences in the remaining two groups. The correlation between the stage of edema on the Yonekawa classification and the mean values of OQ and CQ was 70%.

Disfonias: relação S/Z e tipos de voz

OBJETIVO: verificar o resultado da relação s/z e do tipo de voz em pacientes com diagnóstico de disfonias orgânico-funcionais (DOF) e disfonias funcionais por uso incorreto da voz (DFUIV), bem como a ocorrência das diferentes patologias dentro das DOF. MÉTODOS: 70 indivíduos, de ambos os sexos, entre cinco e 65 anos de idade, atendidos numa clínica-escola, cadastrados em Banco de Dados, entre 1998 e 2006, com DOF e DFUIV, ambos classificados em três subgrupos: casos em que a relação s/z indicava hipercontração, normalidade, e falta de coaptação das pregas vocais durante a fonação. Os tipos de voz foram classificados conforme a ocorrência em: sem alteração; ruidosa; ruidosa, comprimida e/ou apresentando alteração de f0h; ruidosa e/ou apresentando alteração de f0h; e comprimida. RESULTADOS: ocorrência significativa de DOF e de DOF com nódulos vocais; nas DOF e DFUIV, ocorrência significante de relação s/z normal com tempos isolados de /s/ e /z/ abaixo do normal e voz ruidosa. CONCLUSÕES: O resultado da relação s/z foi estatisticamente significativo a favor da faixa de normalidade estabelecida, tanto nos pacientes com diagnóstico de DOF, quanto naqueles com DFUIV, sendo que, em ambos os grupos de pacientes, a voz ruidosa foi a mais freqüente. Dentro das DOF, os nódulos vocais foram significativamente mais freqüentes do que as demais patologias.

Preliminary Study on the Quantitative Analysis of Vocal Loading Effects on Vocal Fold Dynamics Using Phonovibrograms

Objectives:

The purpose of the present study was to determine whether high-speed digital imaging with phonovibrogram (PVG) analysis would identify changes in vocal fold vibratory characteristics following prolonged reading (vocal fatigue) in subjects with normal voice to evaluate the voice effects of vocal loading.

Methods:

Three healthy subjects' larynges were examined with an endoscopic high-speed imaging system at 4 different levels of vocal load. Vocal fold dynamics were segmented and processed by PVGs. The PVG images were quantitatively described by a parameter set enabling an individual characterization of vocal fold dynamics. To reveal differences between the subjects, we performed a linear discrimination analysis. Within each subject, the identification of vocal loading effects was performed by statistical analysis (1-way analysis of variance), and 2-tailed paired t-tests were used as a consistency check between left and right vocal fold sides.

Results:

For each subject, the PVG analysis enabled a precise quantification of the entire range of vocal fold dynamics. Independently of the high-speed videos (vocal loads), each subject could be identified by his or her PVG parameters on linear discrimination analysis. In all subjects, the effect of vocal loading was reflected by alterations of PVG parameters representing the posterior opening and closing dynamics. Evaluation within subjects revealed slight asymmetric vibratory behavior between the left and right vocal folds, confirming earlier assumptions.

Conclusions:

Within the investigated subjects, vocal loading does affect the vibratory characteristics of the vocal folds. Left-right vocal fold vibratory asymmetries do occur in healthy voices and can be identified by PVGs. High-speed digital imaging in combination with PVG analysis seems to be a promising tool for investigation of vocal fold fatigue and disorders resulting even from small dynamic changes.

Evaluation of Voice Acoustic Parameters Related to the Vocal-Loading Test in Professionally Active Teachers with Dysphonia

INTRODUCTION

Teachers are at risk of developing voice disorders. A clinical battery of vocal function tests should include non-invasive and accurate measurements. The quantitative methods (e.g., voice acoustic analysis) make it possible to objectively evaluate voice efficiency and outcomes of dysphonia treatment.

MATERIALS AND METHODS

To identify possible signs of vocal fatigue, acoustic waveform perturbations during sustained phonation were measured before and after the vocal-loading test in 51 professionally active female teachers with functional voice disorders, using IRIS software. All the participants were also subjected to laryngological/phoniatric examination involving videostroboscopy combined with self-estimation by voice handicap index (VHI)-based scale.

RESULTS

The phoniatric examination revealed glottal insufficiency with bowed vocal folds in 35.2%, soft vocal nodules in 31.4%, and hyperfunctional dysphonia with a tendency towards vestibular phonation in 19.6% of the patients. In the VHI scale, 66% of the female teachers estimated their own voice problems as moderate disability. An acoustic analysis performed after the vocal-loading test showed an increased rate of abnormal frequency perturbation parameters (pitch perturbation quotient (Jitter), relative average perturbation (RAP), and pitch period perturbation quotient (PPQ)) compared to the pre-test outcomes. The same was true of pitch-intensity contour of vowel /a:/, an indication of voice instability during sustained phonation.

DISCUSSION AND CONCLUSIONS

The recorded impairments of voice acoustic parameters related to vocal loading provide further evidence of dysphonia. The voice acoustic analysis performed before and after the vocal-loading test can significantly contribute to objective voice examinations useful in diagnosis of dysphonia among teachers.

Effects of Prolonged Loud Reading on Normal Adolescent Male Voices

Purpose

The purpose of this article was to test the effects of vocal loading in healthy, peripubescent teenage boys. It was hypothesized that select acoustic measures, ratings of physical appearance of the larynx, and self-ratings of physical effort and vocal quality in the experimental group would significantly change in response to 2 hr of prolonged loud reading.

Method

In this prospective, repeated measures study, 25 boys aged 13–16 years were randomly assigned to either an experimental group (2 hr of continuous loud reading) or a control group (silent reading with brief periods of conversation). Pre–post acoustic, videoendoscopic, and perceptual data including self-ratings were collected. Postreading recovery changes were tracked by monitoring average reading fundamental frequency (F0) and intensity for 20 min following cessation of the reading task.

Results

The experimental group demonstrated statistically significant differences before and after prolonged loud reading for three variables: F0 ( p < .01), self-ratings of vocal quality ( p < .01), and physical effort ( p < .01). No pre–post changes were evident in the control group. In the experimental group, posttest return of F0 to pretest levels occurred within 20 min. Self-ratings revealed that the boys felt that their voice quality worsened and physical effort increased during the experimental task. Expert ratings did not detect any significant differences in either the perceptual quality of the experimental group’s voices or their videoendoscopic images.

Implications

These findings demonstrate that prolonged loud reading can induce temporary but measurable changes in F0 and in self-perception of vocal function in adolescent males who are experiencing a period of rapid laryngeal growth. The underlying mechanism for these changes remains unclear and warrants continued investigation. Furthermore, the results suggest that in the pubescent male population, comparable vocal loading tasks encountered in daily use should not result in long-term negative effects.