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

OBJECTIVES

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

STUDY DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Experiences of Patients with Unilateral Vocal Fold Paralysis: A Mixed-Methods Study of the Insider's Perspective

OBJECTIVE

Unilateral vocal fold paralysis (UVFP) is often characterized by severe dysphonia and has a significant impact on a patient's communication in daily and vocational situations. Having a better understanding of how UVFP influences quality of life and patient experiences can help improve patient-centered care in this population. Therefore, the purpose of this study was to explore the lived experiences of patients with UVFP.

METHODS

Twenty-five adults with UVFP (age range: 39-84years) participated in the study. Quantitative data were collected from 22 participants, using the Voice Handicap Index (VHI), Dysphonia Severity Index (DSI), and Acoustic Voice Quality Index (AVQI). Qualitative data were collected from 25 individual semistructured interviews, which were recorded, transcribed, and analyzed with the software program NVivo. The interviews were coded using an inductive thematic approach.

RESULTS

Quantitative results showed a mean DSI of - 1.6, mean AVQI of 3.80, and mean VHI of 45.8 in the participant group. A statistically significant, moderate (positive) correlation was found between VHI and time after onset (in years). From the qualitative analysis of the interviews, four main themes were identified: emotional impact, psychosocial impact, physical complaints, and coping strategies. Voice problems caused by UVFP generally had a negative impact on patients' emotional and psychological well-being, with considerable effects on participation, self-identity, and professional activity. Participants demonstrated a combination of problem-focused and emotion-focused coping strategies to accommodate to these issues. Half of the participant group also showed avoidance as a coping style. VHI scores were significantly higher in participants who reported experiencing current emotional and participation problems due to UVFP, and who had not yet accepted their new voice.

CONCLUSION

The themes from this study emphasize the importance of focused anamnesis and emotive counseling in practice, with specific attention to the psychosocial and emotional impact of UVFP.

Immediate and Short-term Effects of Straw Phonation in Air or Water on Vocal Fold Vibration and Supraglottic Activity of Adult Patients with Voice Disorders Visualized with Strobovideolaryngoscopy: A Pilot Study

Purpose The first purpose of this study was to investigate and compare the short-term effects after a semi-occluded vocal tract (SOVT) therapy session consisting of straw phonation (SP) in air or water on vocal fold vibration and supraglottic activity of adult patients with voice disorders, visualized with strobovideolaryngoscopy (SVL). The second purpose of this study was to investigate and compare immediate changes in the patients' vocal fold vibration and supraglottic activity during SP in air or water, visualized with SVL. Methods Twelve adult patients with voice disorders (eight women and four men, mean age 52 years) were assigned randomly to one of two study groups: SP in air or SP in water. Immediately before and after a therapy session of 15 min, participants underwent a rigid SVL to determine the short-term effects of the SP session. At the posttherapy examination, flexible SVL while performing SP was added to determine the effects occurring during SP. The visual-perceptual ratings were performed blindly and in random order by three laryngologists, using the Voice-Vibratory Assessment with Laryngeal Imaging rating form for stroboscopy. ResultsShort-term effects after SP: After the SP-in-air session, the supraglottic mediolateral compression decreased significantly. The SP-in-water session led to significantly increased left vibrational amplitude. Immediate effects during SP: During SP in air, a significantly increased left amplitude and mucosal wave, and significantly decreased mediolateral supraglottic activity, were found. SP in water tended to decrease the vibrational amplitude during performance of the task. A trend toward higher anteroposterior supraglottic compression was observed during both SP in air and water, being more prominent in the latter. Conclusion SP in air led to less false vocal fold adduction and consequently less hyperfunction. The small increment in anteroposterior supraglottic activity during SP in air and water might be related to epilarynx narrowing, an economic phenomenon associated with SOVT exercises. The effects on vibrational amplitude were rather ambiguous. The small reduction in amplitude during SP in water is expected to diminish vocal fold impact stress and therefore creates an ideal basis for voice therapy. The increment in amplitude and mucosal wave during SP in air might indicate insufficient supraglottic pressure to obtain the favorable effects of semi-occlusion. Whether or not the rise in amplitude after the SP-in-water session is due to voice efficiency or voice fatigue remains unknown. Future larger-scale investigation in subgroups of voice patients is needed to explore these hypotheses.

The Occurrence of Laryngeal Pathologies in a Treatment-Seeking Pediatric Population

OBJECTIVES

The purpose of this study was to 1) describe the age- and sex-specific occurrence of laryngeal pathologies in a treatment-seeking pediatric population in the voice unit of Ghent University Hospital, Belgium, and 2) describe this population in terms of vocal parameters, vocal complaints, influencing factors, and treatment history and recommendation.

STUDY DESIGN

Retrospective, observational study.

METHODS

All patient records were analyzed for children (0-18 years) who consulted the ear, nose, and throat department of Ghent University Hospital for the first time between July 2015 and June 2021 with complaints of dysphonia. In total, 103 children (66 males, 37 females) with a mean age of 10.01 years (SD: 3.4, range 3.93-17.96) were included in this study. Laryngeal pathology was diagnosed using a flexible videolaryngo(strobo)scopy. The influence of age and sex on laryngeal etiology (organic/functional voice disorder) was examined using a Welch-modified t test and a Fisher's exact test, respectively.

RESULTS

Organic lesions were observed in 77.7% of the participants, with vocal fold nodules (VFNs) being the most common diagnosis (66.0%). A functional voice disorder was diagnosed in 22.3% of the children. Children with a functional voice disorder are significantly older than children with an organic voice disorder. There was no statistically significant difference between males and females in laryngeal etiology. Mean dysphonia severity index was -2.7 (SD: 3.2, range -9.3 to +3.7), the mean acoustic voice quality index 4.70 (SD: 1.5, range 2.35-8.27), and the mean pediatric voice handicap index 29.8 (SD: 13.6, range 5-60). The occurrence of vocal misuse was mentioned in 80.6% of the patient records.

CONCLUSION

Organic voice disorders, especially VFNs, are predominant in treatment-seeking children with dysphonia. Functional voice disorders become more common with increasing age during childhood. A disordered vocal quality, reduced vocal capabilities and reduced voice-related quality of life were found.

Clinical Experiences of Speech-Language Pathologists in the Rehabilitation of Unilateral Vocal Fold Paralysis

PURPOSE

Unilateral vocal fold paralysis (UVFP) is a neurological voice disorder that is often first treated by a speech-language pathologist (SLP). In literature, little consensus is found regarding voice therapy onset, duration, frequency, and content. The aim of the current study is to investigate the clinical practice of SLPs for treatment of UVFP regarding diagnostics and treatment characteristics. Additionally, the study examined the personal experiences of SLPs regarding UVFP care.

METHOD

An online survey was completed by 37 respondents, all SLPs with experience in treating UVFP. Demographic characteristics, experiences with voice assessments and treatment modalities were examined. Lastly, experiences and opinions of SLPs on evidence-based practice and their own clinical practice were surveyed.

RESULTS

Almost all respondents used a multidimensional voice assessment with findings from laryngovideostroboscopy to assess UVFP. Laryngeal electromyography is not yet integrated in regular clinical practices. The most commonly used vocal techniques were resonant voice exercises, laryngeal manipulation, semioccluded vocal tract exercises (SOVTEs), vocal hygiene, and Vocal Function Exercises, with SOVTEs most often considered effective. A total of 75% of the respondents feel confident treating UVFP, and 87.6% believe it is important to stay updated on evidence-based practice. Variation in therapy timing and dosage was observed, and 48.4% of SLPs usually started early voice therapy within 4 weeks after UVFP onset.

CONCLUSION

Flemish SLPs generally feel confident treating UVFP patients and show interest in improving evidence-based practice. Initiatives to train clinicians further in UVFP care and encouraging SLPs to provide practice-based evidence will enhance the knowledge base for evidence-based practice in UFVP.

Immediate effects of a semi-occluded water-resistance ventilation mask on vocal outcomes in women with dysphonia

INTRODUCTION

Semi-occluded vocal tract exercises (SOVTEs) are frequently used exercises in voice therapy. An important shortcoming to most SOVTEs is the inability to include continuous speech in these exercises. A variation of water-resistance therapy (WRT), during which a patient phonates through a resonance tube ending in water, was developed to include continuous speech: the semi-occluded water resistance ventilation mask (SOVM-WR). The current study investigated the immediate effects of this innovative technique on vocal outcomes of women with dysphonia.

METHODS

A pretest-posttest randomized controlled trial was performed. Twenty female participants were randomly assigned to the experimental SOVM-WR group or the WRT (control) group. A blinded multidimensional voice assessment was conducted before and after a 30-minute therapy session with the assigned technique.

RESULTS

No significant changes were found in acoustic or auditory-perceptual vocal outcomes in either of the groups, except for a significant increase in lowest frequency in both groups. Patient-reported outcomes (PROMs) showed significant improvements of vocal comfort, vocal effort, and voice quality in both groups, and participants indicated that they would use the techniques at home.

CONCLUSIONS

The similar results of the SOVM-WR to WRT and promising PROMs confirm its suitability as an alternative to the latter technique. Potential reasons for a lack of improvement of objective and auditory-perceptual vocal outcomes are vocal fatigue, tube dimensions and immersion, and the small sample size. Large-scale and longitudinal research is needed to examine whether the SOVM-WR has a higher transfer to spontaneous speech than WRT after a full therapy program.

Immediate effects of straw phonation in air or water on the laryngeal function and configuration of female speech-language pathology students visualised with strobovideolaryngoscopy: A randomised controlled trial

BACKGROUND

A promising way to obtain vocal economy and efficiency is by semi-occluding the vocal tract while phonating. Current knowledge about the immediate effects of semi-occluded vocal tract (SOVT) phonation on the laryngeal function and configuration is based mainly on computer modelling or excised larynges studies. In in vivo SOVT studies, electroglottography (EGG) has been the most commonly used laryngeal outcome, showing contradictory results between studies. Therefore, exploring these aspects by direct visualisation of the human larynx during SOVT phonation using strobovideolaryngoscopy (SVL) is needed.

AIMS

The aim of this study was to investigate and compare the immediate effects of straw phonation (SP) in air, SP in 2 cm water, and SP in 5 cm water (with stirring straws), on the laryngeal function and configuration of a homogeneous group of vocally healthy female speech-language pathology students, visualised with flexible SVL.

METHODS & PROCEDURE

A randomised controlled trial was used. Fifty-two female speech-language pathology students (mean age: 18.7 years, SD: 0.6) were assigned randomly to one of three experimental groups or a control group: (1) SP in air, (2) SP in 2 cm water, (3) SP in 5 cm water or (4) [u] phonation with similar soft onset and slightly pursed lips as in SP but without a straw (control group). The participants underwent flexible SVL during habitual [u] phonation, followed by the specific SOVT exercise of their group assignment. All video samples were evaluated randomly and blindly by two experienced investigators using the Voice-Vibratory Assessment with Laryngeal Imaging (VALI) rating form, first independently and then by consensus.

OUTCOME & RESULTS

Compared to habitual phonation, the vibrational amplitude decreased during SP in 5 cm water and SP in 2 cm water, being more prominent in the first, more flow-resistant exercise. The mucosal wave also decreased during SP in 5 cm water. The anteroposterior (AP) supraglottic compression similarly increased during SP in air, SP in 2 cm water, and SP in 5 cm water. Further, a rise in mediolateral (ML) compression and a decrease in phase symmetry and regularity were found during SP in 2 cm water. A similar decrease in regularity was observed during SP in 5 cm water.

CONCLUSIONS & IMPLICATIONS

Both SP in air and SP in water cause positive immediate laryngeal effects for voice training opportunities. More AP supraglottic activity found during each SP exercise might indicate epilarynx narrowing, an economic phenomenon associated with SOVT. Immersing the straw in water additionally diminished the vibrational amplitude, lowering vocal fold impact stress and risk for phonotrauma during the exercise. The decreased regularity of the vibrational cycles during SP in water might be due to the varying back pressure created by the water bubbling. The impact of SP in water on ML supraglottic compression needs further investigation.

WHAT THIS PAPER ADDS

What is already known on the subject A promising way to obtain vocal economy and efficiency is by semi-occluding the vocal tract while phonating. Current knowledge about the immediate effects of semi-occluded vocal tract (SOVT) phonation on the laryngeal function and configuration is based mainly on computer modelling or excised larynges studies. In in vivo SOVT studies, electroglottography (EGG) has been the most commonly used laryngeal outcome, showing contradictory results between studies. Therefore, exploring these aspects by direct visualisation of the human larynx during SOVT phonation using strobovideolaryngoscopy (SVL) is needed. What this paper adds to existing knowledge Group results of the current study generally support earlier computer modelling and in vivo studies, strengthening the current SOVT knowledge. Both SP in air and SP in water cause positive immediate laryngeal effects for voice training opportunities. More anteroposterior (AP) supraglottic activity found during each SP exercise might indicate epilarynx narrowing, an economic phenomenon associated with SOVT. Immersing the straw in water additionally diminished the vibrational amplitude, lowering vocal fold impact stress and risk for phonotrauma during the exercise. The decreased regularity of the vibrational cycles during SP in water might be due to the varying back pressure created by the water bubbling. The impact of SP in water on ML supraglottic compression needs further investigation. What are the potential or actual clinical implications of this work? Current results support that both SP in air and SP in water can be useful exercises in voice training. SP in water has shown the additional gain of lowering the vibrational amplitude during the exercise, hence supporting its appropriateness for vocal warm-ups by minimising vocal fold impact stress and the risk of phonotrauma. In the future, large-scale randomised controlled trials in other subgroups of voice users, including dysphonic patients, are needed to support evidence-based practice. SVL can facilitate the search for individualised training and therapy approaches.

Voice Outcome of Glottoplasty in Trans Women

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Peer attitudes towards adolescents with speech disorders due to cleft lip and palate

BACKGROUND AND AIMS

Individuals with speech disorders are often judged more negatively than peers without speech disorders. A limited number of studies examined the attitudes of adolescents toward peers with speech disorders due to a cleft lip with or without a cleft of the palate (CL ± P). Therefore, the aim of the present study was to investigate the attitudes of peers toward the speech of adolescents with CL ± P.

METHOD

Seventy-eight typically developing adolescents (15-18 years, 26 boys, 52 girls) judged audio and audiovisual samples of two adolescents with CL ± P based on three attitude components, i.e., cognitive, affective, and behavioral. The degree of speech intelligibility was also scored by their peers. The study investigated whether the three attitudes were determined by speech intelligibility or appearance of an individual with CL ± P. Furthermore, the influence of knowing someone with a cleft, the age, and gender of the listeners on their attitudes were explored.

RESULTS

A significantly positive correlation was found between the speech intelligibility percentage and the three different attitude components: more positive attitudes were observed when the speech intelligibility of the speaker was higher. A different appearance due to a cleft lip does not lead to more negative attitudes. Furthermore, boys seem to have more negative attitudes toward individuals with CL ± P compared to girls.

CONCLUSION

This study provided additional evidence that peers show more negative attitudes toward adolescents with less intelligible speech due to CL ± P. Intervention should focus on changing the cognitive, affective, and behavioral attitudes of peers in a more positive direction and remove the stigma of patients with a cleft. Further research is needed to verify these results.

Longitudinal Vocal Outcomes and Voice-Related Quality of Life After Selective Bilateral Laryngeal Reinnervation: A Case Study

PURPOSE

Bilateral vocal fold paralysis (BVFP) is a severe disorder that can result in respiratory, swallowing, and voice-related problems. Most surgical treatments do not restore laryngeal function and often need to compromise voice quality to preserve respiratory function. Laryngeal reinnervation (LR) may offer a solution to this problem, but literature on longitudinal outcomes of this procedure is scarce. This study aims to report the longitudinal vocal outcomes of BVFP after LR and subsequent voice therapy.

METHOD

The case of a 23-year-old man with BVFP after a traumatic dissection of both recurrent laryngeal nerves is described. Selective bilateral LR of both adductors and abductors was performed 5 months after the onset of BVFP. Voice therapy was provided after the LR procedure. Multidimensional voice assessments, including acoustic, perceptual, and patient-reported outcome measures (PROMs), were conducted 2, 5, 6.5, 8, and 31 months after LR.

RESULTS

An improvement of vocal capabilities and voice quality was noticed 6.5 months after LR, after 4.5 months of voice therapy, with normative values after 2.5 years. PROMs showed an improvement of voice-related quality of life, but some limitations to activities of daily living were still present. Inspiratory arytenoid abduction was not observed on laryngeal videostroboscopic findings in this patient, but tracheostomy was not required.

CONCLUSIONS

Voice therapy after LR helps establish healthy and efficient voice use without increasing compensatory hyperfunctional behavior. More research is needed to examine potential merits of voice therapy in the rehabilitation of vocal and respiratory functions after LR.

EASE-NL: Cross-Cultural Adaptation and Validation of the Dutch Version of the Evaluation of Ability to Sing Easily

OBJECTVES

The Evaluation of the Ability to Sing Easily (EASE) is a self-rating tool that is used to assess the singer's perceptions of the current singing voice status. The purpose of this study was to develop and validate a Dutch translation of the EASE.

METHODS

The original version of the EASE was translated and adapted to Dutch according to the recommendations of the Quality of Life Special Interest Group - Translation and Cultural Adaptation group. Subsequently, the questionnaire was individually completed by 70 singers with a mean age of 35.2 years before and after a singing activity, together with a demographic questionnaire and the Dutch Singing Voice Handicap Index 10 (SVHI-10-NL). Two groups of singers were included between September and June 2020: a group of healthy singers (n = 54) and a group of dysphonic singers (n = 16). Internal and external consistency, construct and criterion validity, test-retest and split-half reliability were calculated using Cronbach's alpha coefficients, Student's t-test, the paired Wilcoxon tests and Pearson correlation coefficients. Furthermore, the impact of sex and age and the diagnostic accuracy of the EASE-NL was measured using the Mann Whitney U-test, the One Way ANOVA and the Brown Forsythe ANOVA-test.

RESULTS

The internal consistency of the EASE was considered good. For the external consistency, the Pearson correlation coefficient showed a positive correlation between the total score of the EASE-NL and the SVHI-10-NL. Dysphonic singers scored significantly higher compared to singers without voice problems and no differences were found between the pre and post singing condition in both groups. Pearson correlations coefficients showed a strong positive correlation between the test and retest condition and between the subscales. A ROC-curve analysis showed a cut-off score of 12.5, with a sensitivity level of 75.0% and a specificity level of 74.1%. No differences for sex and age were found.

CONCLUSIONS

The original English version of the EASE was translated and validated in Dutch. The EASE-NL is found to be a valid and reliable self-reported tool to assess singer's perceptions of the current status of their singing voice.

Effects of voice therapy in children with vocal fold nodules: A systematic review

BACKGROUND

Vocal fold nodules (VFNs) are the main cause of paediatric dysphonia. Voice therapy is recommended as the preferable treatment option for VFNs in children.

AIM

The aim of this systematic review is to provide an overview of the existing literature concerning the effects of voice therapy in children with VFNs.

METHODS & PROCEDURES

This systematic literature review was developed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (via PubMed) and Embase were searched and the grey literature was checked. The search strategy was based on three concepts: VFNs, voice therapy and children. Two examiners independently determined article eligibility and extracted all relevant data from the included studies. The methodological quality of the included study was assessed using the QualSyst tool.

MAIN CONTRIBUTIONS

By identifying, evaluating and summarizing the results of all relevant studies about voice therapy in paediatric VFNs, this systematic review makes the available evidence more accessible to voice therapists, otolaryngologists and other relevant stakeholders.

CONCLUSIONS & IMPLICATIONS

24 studies were included in this systematic review. Eight studies (8/24) reported a significant improvement for at least one outcome parameter after voice therapy. However, five papers (5/24) could not demonstrate significant changes after voice therapy. All studies that did not test for significance (11/24) found improvements for one or more outcome parameters. The overall quality of the included studies is adequate (55%). In sum, there is some evidence that voice therapy is effective in children with VFNs, but further well-designed research, especially randomized controlled trials, is necessary to confirm these results.

WHAT THIS PAPER ADDS

What is already known on the subject Voice therapy is preferable in children with VFNs because of the phonotraumatic nature of the nodules and the associated high recurrence rate after phonosurgery. Most voice therapists in clinical practice offer an eclectic voice therapy programme, consisting of direct and indirect voice therapy techniques. What this study adds to existing knowledge This systematic review provides a clear overview of the available evidence concerning the effects of voice therapy in paediatric VFNs. There is some evidence that voice therapy is an effective treatment option in children with VFNs, but well-designed research is scarce on this subject. What are the potential or actual clinical implications of this work? This review shows that effectiveness studies with strong designs are very scarce in children with VFNs. Clinicians should be aware that few therapy techniques have been thoroughly investigated in this population. However, this review may guide voice therapists when creating a treatment plan for a child with VFNs because it identifies, evaluates and summarizes the results of all relevant individual studies about voice therapy in paediatric VFNs. Voice therapy seems to be effective in treating paediatric patients with VFNs, given the fact that a considerable number of included studies report significant improvements after voice therapy. Both direct and indirect therapy approaches appear to have a positive effect on the phonation of children with VFNs.

Voice Quality of Choir Singers and the Effect of a Performance on the Voice

BACKGROUND

The voice use of choir singers is understudied despite the imbalance of high vocal demands versus low vocal education, and consequently increased risk for voice problems. Also, there is a lack of information on the effects of a performance on choristers' voices. Available studies included performances of at least one hour. To date, no studies investigated the effects of a choir performance with a duration resembling vocal warm-ups.

PURPOSE

The first purpose of this study was to determine the voice quality, capacities, symptoms and voice-related quality of life of choir singers. Secondly, the effect of a short choir performance, resembling warm-up duration (15 minutes), on the choristers' voices was investigated.

METHODS

A randomized controlled trial was used. Thirty adult choir singers (25 women, 5 men; mean age: 32 years) were assigned randomly to an experimental group or a control group. Participants in the experimental group sung in choir for 15 minutes immediately after their pre voice assessment, whereas the control group was instructed to have standard voice use (one-on-one conversation with the investigator, no singing) across that time span. A second voice assessment was repeated afterwards.

RESULTS

The choir singers showed excellent voice quality and capacities with mean scores on the Dysphonia Severity Index and Acoustic Voice Quality Index of 7.5 and 2.0, respectively. Auditory-perceptually, the mean grade score was 5/100 corresponding with a normal to mildly deviant voice quality. Patient-reported outcome measures showed mean deviant scores, indicating a considerable singing voice handicap. The choir singers seem vulnerable for stress with a high occurrence rate of 76.7% (23/30). Compared with the control group, the Dysphonia Severity Index significantly improved, whereas the self-perceived presence of vocal fatigue and complaints increased after 15 minutes of choir singing. Fundamental frequency increased in both groups, being more outspoken in the experimental group.

CONCLUSIONS

Choir singers show excellent voice quality and capacities, that further improve after a short choir performance of 15 minutes. Vocal fatigue and complaints, on the other hand, already increased after that short time span. Realizing that vocal load is much higher in real-life rehearsals, competitions and performances, choristers deserve and need a qualitative voice training and a strict follow-up. Future research should focus on effective vocal warm-up and cool-down programs for this population.

Listeners' attitudes towards voice disorders: An interaction between auditory and visual stimuli

OBJECTIVE

People with dysphonia are judged more negatively than peers with normal vocal quality. This preliminary study aims to (1) investigate correlations between both auditory-perceptual and objective measures of vocal quality of dysphonic and non-dysphonic speakers and attitudes of listeners, and (2) discover whether these attitudes towards people with dysphonia vary for different types of stimuli: auditory (A) stimuli and combined auditory-visual (AV) stimuli. Visual (V) stimuli were included as a control condition.

METHOD

Ten judges with no experience in the evaluation of dysphonia were asked to rate A, AV and V stimuli of 14 different speakers (10 dysphonic and 4 non-dysphonic speakers) Cognitive attitudes, evaluation of voice characteristics and behavioral attitudes were examined. Pearson and Spearman correlation coefficients were calculated to examine correlations between both Dysphonia Severity Index (DSI) values and perceptual vocal quality as assessed by a speech-language pathologist (PVQ_SLP) or perceptual vocal quality as assessed by the judges (PVQ_judge). Linear mixed model (LMM) analyses were conducted to investigate differences between speakers and stimuli conditions.

RESULTS

Statistically significant correlations were found between both perceptual and objective measures of vocal quality and mean attitude scores for A and AV stimuli, indicating increasingly negative attitudes with increasing dysphonia severity. Fewer statistically significant correlations were found for the combined AV stimuli than for A stimuli, and no significant correlations were found for V stimuli. LMM analyses revealed significant group effects for several cognitive attitudes.

CONCLUSION

Generally, people with dysphonia are judged more negatively by listeners than peers without dysphonia. However, the findings of this study suggest a positive influence of visual cues on the judges' cognitive and behavioral attitudes towards dysphonic speakers. Further research is needed to investigate the significance of this influence.

Knowledge of the Voice in the Teachers' Population and their Ability to Refer Children with Voice Disorders to a Speech-Language Pathologist

OBJECTIVES

The objectives of this study were to investigate (1) the knowledge of primary school teachers regarding voice and voice disorders, (2) the primary school teacher's ability to identify and refer a dysphonic child to a speech-language pathologist (SLP), and (3) potential contributing factors that might affect this ability.

METHOD AND MATERIALS

Thirty-one primary school teachers (30 women, one man) with a mean age of 33 years (range: 22-57 years; SD: 11.1 years) were included in this study. They filled out an online questionnaire, gathering demographic information, estimations of their knowledge regarding voice and voice disorders, and their ability to refer a dysphonic child to an SLP. Furthermore, they completed an online quiz (maximum score: 9) with basic questions about the voice, vocal health and voice disorders.

RESULTS

Most teachers (58.1%) rated their knowledge as basic, 16.1% as adequate and 25.8% as good. One out of four teachers (25.8%) received voice-related information during their education. A substantial part (38.7%) gathered information through other channels, such as voice therapy. Almost all participants (90%) reported to have no or little experience with dysphonic children. Half of them (51.6%) felt unsure about their ability to refer a dysphonic child to an SLP, and 54.8% were willing to attend extra voice workshops. A significant association was found between the estimated knowledge regarding voice (disorders) and attendance of voice therapy (P = 0.020). More than half of the teachers who attended voice therapy (57.1%) estimated their voice-related knowledge as good, compared to only 16.7% of the teachers who did not attend voice therapy. Moreover, a significant association was found between the years of teaching experience and the quiz total score (P = 0.040). The majority of the teachers with the least teaching experience (57.1%) achieved a score between 4 and 6, whereas the teachers with more experience achieved a score between 7 and 9.

CONCLUSION

This study suggests that the voice-related knowledge of primary school teachers is limited. Consequently, teachers do not feel confident in referring a dysphonic child to an SLP. As teachers can be important sources in indirect assessment of pediatric dysphonia, they need to be well informed and extensively trained in using voice screening protocols. Interdisciplinary cooperation between SLPs and teachers should be optimized to provide the best available care and improve the children's quality of life.

Validity and Reliability of the Dutch Children's Voice Handicap Index-10

OBJECTIVES

Voice-related quality of life (Qol) questionnaires provide the clinician with information regarding the impact of voice disorders on the patient's well-being. The available voice-related QoL tools for Dutch-speaking children are parent-proxy in nature. However, the use of proxy measurements has been debated in the literature. The Children's Voice Handicap Index-10 (CVHI-10) is a self-reported QoL tool for dysphonic children. Therefore, the aim of this study is to develop and validate a Dutch version of the CVHI-10.

STUDY DESIGN

Observational, prospective, cross-sectional study.

METHODS

The original version of the CVHI-10 was translated and adapted to Dutch according to the recommendations of the Quality of Life Special Interest Group - Translation and Cultural Adaptation group. Subsequently, the questionnaire was individually completed by 77 children (dysphonic group: n = 30, control group: n = 47) between eight and 14 years. In order to investigate test-retest reliability, 50% of the participants were asked to complete the questionnaire twice with an interval of 2 weeks. Internal consistency, test-retest reliability and construct validity were calculated. A receiver operating characteristic (ROC) analysis was conducted to check the sensitivity and specificity levels of the instrument.

RESULTS

Internal consistency measured with Cronbach's alpha coefficient was 0.745. Test-retest reliability measured with intraclass correlation coefficients was 0.718. Mean total CVHI-10 score was 6.17 ± 2.7 in the dysphonic group and 2.68 ± 2.6 in the control group. The difference in total score between the groups was statistically significant (P < 0.001), suggesting that the tool has good construct validity. ROC analysis demonstrated moderate diagnostic accuracy (area under the curve = 0.869) and suggested a cut-off score of 3.5.

CONCLUSIONS

The Dutch CVHI-10 is the first self-reported voice-related QoL tool for dysphonic Dutch-speaking children. It is a valid, reliable and sensitive tool to assess the impact of a voice disorder on the child's well-being.

Long-term voice quality outcome after thyroidectomy without laryngeal nerve injury: a prospective 10 year follow up study

PURPOSE

This study investigates the long-term voice outcome of thyroidectomy up to 10 years after the surgery using a longitudinal prospective study design.

METHODS

Eighteen participants (6 men and 12 women, mean age: 54 years) who underwent a thyroidectomy between September 2006 and May 2007 were included in this study. A voice assessment protocol consisting of subjective (videolaryngostroboscopic evaluation, auditory- perceptual evaluation, patients' self-report) and objective voice assessments (maximum performance task, acoustic analysis, voice range profile and Dysphonia Severity Index) was used to evaluate the participants' pre- and postoperative voice. Voice measurements were compared before and one week, six weeks, three months and 10 years after the surgery.

RESULTS

No significant differences over time in auditory-perceptual and objective voice parameters were found, except for shimmer. Only in the first postoperative condition, significantly more patients reported vocal complaints. A progressive amelioration of the vocal folds' movement patterns was observed in the postoperative conditions.

CONCLUSION

The findings of this small longitudinal prospective study suggest that thyroidectomy without laryngeal nerve injury does not cause a permanent deterioration of the laryngeal aspect or function, vocal fold behavior and the self-perceived, perceptual and objective vocal quality. The increase of the shimmer 10 years post-thyroidectomy may be related to vocal aging.

The Patient's Opinion Regarding Different Service Delivery Models for Voice Therapy

Purpose The purpose of this study was to compare the voice patient's opinion regarding three service delivery models for voice therapy: a short-term intensive voice therapy with individual sessions (IVT-I), a short-term intensive voice therapy with group sessions (IVT-G), or a long-term traditional voice therapy with individual sessions (TVT). Method Forty-six adult voice patients who followed either IVT-I, IVT-G, or TVT were contacted by e-mail with the request to fill in an online questionnaire reviewing their opinion about the received therapy. Several items concerning satisfaction, progress, time-related variables, transfer, and need for further therapy were scored by means of visual analog scales. Participants were also asked whether or not they continued voice therapy after the study. Results There were no significant differences between the three groups regarding the patients' perception of vocal quality improvement, degree of resolution of the voice disorder, duration of one session, total therapy duration, degree of transfer, need for further therapy, and actual continuation of therapy. A higher satisfaction rate was found for patients of the IVT-I and TVT groups than patients of the IVT-G group. The IVT-I group rated the therapy as too frequent compared with the TVT group who rated the frequency as optimal. Conclusion Results suggest that patients are equally satisfied and perceive a similar progress after individual short-term intensive voice therapy and individual long-term traditional voice therapy. This finding creates flexibility in selecting time-related variables depending on the specific case and situation. Patients who received individual therapy were more satisfied than patients who received group therapy. Future larger scale investigation is needed to confirm these results.

Vocal Quality, Symptoms, and Habits in Musical Theater Actors

PURPOSE

The purpose of this study was to measure and compare the voice characteristics and vocal complaints and habits of musical theater actors and musical theater students.

METHOD

Thirty participants were included in the study, 18 musical theater students and 12 professional musical theater actors. Vocal quality was measured by the multiparameter indices Dysphonia Severity Index (DSI) and Acoustic Voice Quality Index (AVQI). A perceptual evaluation of the speaking voice was performed using the GRBASI scale. All participants completed the Voice Handicap Index (VHI), the VHI adapted to the singing voice, the Vocal Tract Discomfort (VTD) Scale and the Corporal Pain Scale.

RESULTS

Excellent scores for DSI (resp. 7.3, 7.1) and AVQI (resp. 2.6, 2.5) were found in the musical theater actors and students. All participants reported at least two symptoms of VTD and the mean scores for the VHI adapted to the singing voice were located in the clinical zone. Musical theater students reported significantly more VTD and pain symptoms compared to the professionals. No significant differences in perceptual and objective voice characteristics were found between musical theater actors and students. A higher presence of vocal misuse and stress in the students was observed.

CONCLUSION

Musical theater students and actors are elite vocal performers with comparable excellent objective vocal measures (DSI, AVQI). In both groups, an increased number of VTD and complaints of the singing voice were reported. Especially students were vulnerable for stress, vocal misuse, VTD, and pain symptoms. The findings suggest that musical theater actors are a risk group for developing voice disorders requiring multidimensional voice assessment and voice care.

Immediate Effects of a Semi-Occluded Water Resistance Ventilation Mask on Objective and Subjective Vocal Outcomes in Musical Theater Students

Background Traditional semi-occluded vocal tract exercises (SOVTEs) are restricted to single-phoneme tasks due to the semi-occlusion at the mouth, which hinders full articulation, continuous speech, and singing. Innovative SOVTEs should overcome this limitation by creating the semi-occlusion outside the oral cavity. Purpose The purpose of this study was to investigate the immediate effects of a semi-occluded water resistance ventilation mask, which allows for continuous speech and singing, on objective (voice range, multiparametric voice quality indices) and subjective (auditory-perceptual, self-report) vocal outcomes in musical theater students. Method A pre-/posttest randomized controlled trial was used. Twenty-four musical theater students (16 women and eight men, with a mean age of 21 years) were randomly assigned into a study group and a control group. The study group received a vocal warm-up session with the innovative water resistance ventilation mask (tube attached to the mask "outside" the mouth), whereas the control group received the traditional water resistance approach (tube "inside" the mouth). Both sessions lasted 30 min and were similar with respect to vocal demand tasks. A multidimensional voice assessment including objective and subjective outcomes was performed pre- and posttraining by an assessor blinded to group allocation. Results The Dysphonia Severity Index significantly and similarly increased (improved) in both the study and control groups, whereas the Acoustic Voice Quality Index solely decreased (improved) in the control group. The intensity range significantly decreased (worsened) and the semitone range significantly increased (improved) in the study group, whereas no differences in voice range profile were found in the control group. Auditory-perceptually, a more strenuous speaking voice was noticed after the use of the traditional water resistance approach. The subjects perceived both SOVTEs as comfortable vocal warm-up exercises that decrease the amount of effort during speaking and singing, with a slight preference for the water resistance ventilation mask. Conclusions Both the innovative water resistance ventilation mask and the traditional water resistance exercise seem effective vocal warm-up exercises for musical theater students. The additional articulatory freedom of the mask might increase the phonatory comfort and the practical implementation of SOVTEs in the daily vocal warm-up of (future) elite vocal performers. The hypothesis of a higher transfer to continuous speech or singing in the mask condition has not been supported by the current study. Larger scale investigation and longer term follow-up studies are needed to confirm these preliminary results. Supplemental Material https://doi.org/10.23641/asha.11991549.

Massed Versus Spaced Practice in Vocology: Effect of a Short-Term Intensive Voice Therapy Versus a Long-Term Traditional Voice Therapy

Purpose The aim of this study was to compare the effect of a short-term intensive voice therapy (IVT) with a long-term traditional voice therapy (TVT) on the vocal quality, vocal capacities, psychosocial impact, vocal tract discomfort, laryngological anatomy/physiology, and session attendance of patients with dysphonia. An additional comparison was made between an individual IVT (IVT-I) and a group IVT (IVT-G). Method A longitudinal, prospective controlled trial was used. Forty-six adults diagnosed with dysphonia were assigned to 1 of the 3 treatment groups. The IVT groups practiced with a frequency of 1 hr 20 min a day and a duration of 2 weeks. The TVT group practiced with a frequency of two 30-min sessions a week and a duration of 6 months. Both therapy programs were content-identical and guided by the same voice therapist. A multidimensional voice assessment consisting of both objective (maximum performance task, aerodynamic measurements, voice range profile, acoustic analysis, multiparametric voice quality indices) and subjective (subject's self-report, auditory-perceptual evaluation, flexible videolaryngostroboscopy) outcomes was used to evaluate the participants' voice. Results IVT made an equal progress in only 2 weeks and 12 hr of therapy compared with TVT that needed 6 months and 24 hr of therapy. IVT-I and IVT-G showed comparable results. Session attendance was clearly higher in IVT compared with TVT. Long-term follow-up results (1 year) were positive for the 3 groups, except for the self-reported psychosocial impact that increased in the IVT-I group. Conclusions Short-term IVT is at least equally effective in treating patients with dysphonia as long-term TVT. Group treatment seemed as effective as individual treatment. Attendance and cost-effectiveness are important advantages of IVT. A potential drawback might be an insufficient psychosocial progress. The golden mean between intensive and traditional treatment might therefore be an achievable, effective, and efficient solution for everyday clinical practice. Supplemental Material https://doi.org/10.23641/asha.7761872.

Effect of three semi-occluded vocal tract therapy programmes on the phonation of patients with dysphonia: lip trill, water-resistance therapy and straw phonation

BACKGROUND

To date, the immediate effects of a semi-occluded vocal tract (SOVT) configuration have been thoroughly demonstrated. However, it is not yet sufficiently confirmed whether a therapy programme (i.e. longer than one session) using SOVT exercises leads to an enhanced phonation and improved vocal quality.

AIMS

The aim of this study was to investigate the effect of three SOVT therapy programmes: lip trill, water-resistance therapy (WRT) and straw phonation, on the vocal quality, vocal capacities, psychosocial impact and vocal tract discomfort of patients with dysphonia.

METHODS & PROCEDURES

A blocked-randomized sham-controlled trial was used. Thirty-five patients with dysphonia (mean age = 21 years; 33 women, two men) were assigned to either a lip trill group, a WRT group, a straw phonation group or a control group using blocked randomization. The lip trill, WRT and straw phonation groups practised their respective SOVT exercise across 3 weeks, whereas the control group received a sham treatment across the same time span. A multidimensional voice assessment consisting of both objective (multiparametric indices: Dysphonia Severity Index (DSI), Acoustic Voice Quality Index (AVQI)) and subjective (subject's self-report, auditory-perceptual evaluation) vocal outcomes was performed by a blinded assessor pre- and post-therapy.

OUTCOMES & RESULTS

Lip trill and straw phonation therapy led to a significant improvement in DSI. Auditory-perceptual grade and roughness significantly decreased after straw phonation. Lip trill and WRT both led to a significant decrease in Voice Handicap Index. Subjects reported a better self-perceived vocal quality and a more comfortable voice production after WRT. No changes were found after the sham treatment in the control group.

CONCLUSIONS & IMPLICATIONS

Results suggest that SOVT therapy programmes including lip trill or straw phonation can improve the objective vocal quality in patients with dysphonia. Auditory-perceptual improvements were found after straw phonation therapy, whereas psychosocial improvements were found after lip trill and WRT. Patients seem to experience more comfort and a better self-perceived vocal quality after WRT. This study supports the use of the three SOVT therapy programmes in clinical practice. They all had a positive impact on one or more outcomes of the multidimensional voice assessment. Strikingly, vocal quality outcomes were not in line with the subject's opinion. Larger-scale investigation is needed to support these preliminary findings.

Massed versus spaced practice in vocology: effect of a short-term intensive voice training versus a longer-term traditional voice training

BACKGROUND

In contrast with most medical and pharmaceutical therapies, the optimal dosage for voice therapy or training is unknown.

AIMS

The aim of this study was to compare the effect of a short-term intensive voice training (IVT) with a longer-term traditional voice training (TVT) on the vocal quality and vocal capacities of vocally healthy non-professional voice users.

METHODS & PROCEDURES

A pre-/post-test randomized control group design with follow-up measurements was used. Twenty healthy female non-professional voice users with a mean age of 21.7 years (range = 20-24 years) were randomly assigned into a short-term IVT group (n = 10) or a longer-term TVT group (n = 10). Both groups received an identical 6-h lasting voice training. Only the distribution of practice varied between the groups: 2 h a day for 3 consecutive days for the IVT group versus two 30-min sessions a week for 6 weeks for the TVT group. In both groups, a voice assessment protocol consisting of subjective (questionnaire, participant's self-report, auditory-perceptual evaluation) and objective (maximum performance task, acoustic analysis, voice range profile, dysphonia severity index) measurements and determinations was used to evaluate the participants' voice pre- and post-training and at 6 weeks follow-up. Groups were compared over time using linear mixed models and generalized linear mixed models. Within-group effects of time were determined using post-hoc pairwise comparisons with Bonferroni corrections.

OUTCOMES & RESULTS

No significant time-by-group interactions were found for any of the outcome measures, indicating no significant differences in evolution over time between the groups. Significant time effects were found for maximum phonation time, lowest intensity, lowest frequency, highest frequency and dysphonia severity index, all improving over time in both groups. More in-depth within-group analyses indicate a preference for the IVT group regarding the evolution of maximum phonation time, lowest frequency and dysphonia severity index, and a preference for the TVT group regarding the evolution of lowest intensity.

CONCLUSIONS & IMPLICATIONS

Short-term IVT may be equally, or even more, effective in training vocally healthy non-professional voice users compared with longer-term TVT.

Brain activity during phonation in healthy female singers with supraglottic compression: an fMRI pilot study

This pilot study evaluated the usability of functional magnetic resonance imaging (fMRI) to detect brain activation during phonation in healthy female singers with supraglottic compression. Four healthy female classical singers (mean age: 26 years) participated in the study. All subjects had normal vocal folds and vocal characteristics and showed supraglottic compression. The fMRI experiment was carried out using a block design paradigm. Brain activation during phonation and exhalation was analyzed using Brain Voyager software (Brain Innovation B.V., Maastricht, The Netherlands). An fMRI data analysis showed a significant effect of phonation control in the bilateral pre/postcentral gyrus, and in the frontal, cingulate, superior and middle temporal gyrus, as well as in the parietal lobe, insula, lingual gyrus, cerebellum, thalamus and brainstem. These activation areas are consistent with previous reports using other fMRI protocols. In addition, a significant effect of phonation compared to exhalation control was found in the bilateral superior temporal gyrus, and the pre/postcentral gyrus. This fMRI pilot study allowed to detect a normal pattern of brain activity during phonation in healthy female singers with supraglottic compression using the proposed protocol. However, the pilot study detected problems with the experimental material/procedures that would necessitate refining the fMRI protocol. The phonation tasks were not capable to show brain activation difference between high-pitched and comfortable phonation. Further fMRI studies manipulating vocal parameters during phonation of the vowels /a/ and /i/ may elicit more distinctive hemodynamic response (HDR) activity patterns relative to voice modulation.

Short-Term Effect of Two Semi-Occluded Vocal Tract Training Programs on the Vocal Quality of Future Occupational Voice Users: "Resonant Voice Training Using Nasal Consonants" Versus "Straw Phonation"

PURPOSE

The purpose of this study was to determine the short-term effect of 2 semi-occluded vocal tract training programs, "resonant voice training using nasal consonants" versus "straw phonation," on the vocal quality of vocally healthy future occupational voice users.

METHOD

A multigroup pretest-posttest randomized control group design was used. Thirty healthy speech-language pathology students with a mean age of 19 years (range: 17-22 years) were randomly assigned into a resonant voice training group (practicing resonant exercises across 6 weeks, n = 10), a straw phonation group (practicing straw phonation across 6 weeks, n = 10), or a control group (receiving no voice training, n = 10). A voice assessment protocol consisting of both subjective (questionnaire, participant's self-report, auditory-perceptual evaluation) and objective (maximum performance task, aerodynamic assessment, voice range profile, acoustic analysis, acoustic voice quality index, dysphonia severity index) measurements and determinations was used to evaluate the participants' voice pre- and posttraining. Groups were compared over time using linear mixed models and generalized linear mixed models. Within-group effects of time were determined using post hoc pairwise comparisons.

RESULTS

No significant time × group interactions were found for any of the outcome measures, indicating no differences in evolution over time among the 3 groups. Within-group effects of time showed a significant improvement in dysphonia severity index in the resonant voice training group, and a significant improvement in the intensity range in the straw phonation group.

CONCLUSIONS

Results suggest that the semi-occluded vocal tract training programs using resonant voice training and straw phonation may have a positive impact on the vocal quality and vocal capacities of future occupational voice users. The resonant voice training caused an improved dysphonia severity index, and the straw phonation training caused an expansion of the intensity range in this population.

Effect of two isolated vocal facilitating techniques glottal fry and yawn-sigh on the phonation of female speech-language pathology students: A pilot study

OBJECTIVE

The purpose of this study was to determine the effect of two isolated vocal facilitating techniques, glottal fry and yawn-sigh, on the phonation of vocally healthy female speech-language pathology (SLP) students.

STUDY DESIGN

A multigroup pretest-posttest design was used.

METHODS

A group of thirty-six healthy female SLP students with a mean age of 18.1 years were assigned into three groups: a glottal fry group (practicing the facilitating technique glottal fry across 18 weeks, n=12), a yawn-sigh group (practicing the facilitating technique yawn-sigh across 18 weeks, n=12) and a control group (receiving no facilitating techniques, n=12). To compare vocal measures before and after this training period, an identical objective voice assessment protocol (maximum performance task, acoustic analysis, voice range profile and Dysphonia Severity Index) was performed in the three groups. Groups were compared over time using linear mixed models. Within-group effects of time were determined using post hoc pairwise comparisons.

RESULTS

Glottal fry resulted in a significant decrease in lowest and highest intensity. Yawn-sigh resulted in a significant increase in fundamental frequency, a significant decrease in shimmer and noise-to-harmonic ratio, and a significant increase in highest intensity.

CONCLUSIONS

Yawn-sigh may have a positive effect on the phonation of female vocally healthy future SLPs, whereas results are less supportive for using glottal fry in training this population's voice.

Short-term and long-term test-retest reliability of the Nasality Severity Index 2.0

PURPOSE

The Nasality Severity Index 2.0 (NSI 2.0) forms a new, multiparametric approach in the assessment of hypernasality. To enable clinical implementation of this index, the short- and long-term test-retest reliability of this index was explored.

METHODS

In 40 normal-speaking adults (mean age 32y, SD 11, 18-56y) and 29 normal-speaking children (mean age 8y, SD 2, 4-12y), the acoustic parameters included in the NSI 2.0 (i.e. nasalance of the vowel /u/ and an oral text, and the voice low tone to high tone ratio (VLHR) of the vowel /i/) were obtained twice at the same test moment and during a second assessment two weeks later. After determination of the NSI 2.0, a comprehensive set of statistical measures was applied to determine its reliability.

RESULTS

Long-term variability of the NSI 2.0 and its parameters was slightly higher compared to the short-term variability, both in adults and in children. Overall, a difference of 2.82 for adults and 2.68 for children between the results of two consecutive measurements can be interpreted as a genuine change. With an ICC of 0.84 in adults and 0.77 in children, the NSI 2.0 additionally shows an excellent relative consistency. No statistically significant difference was withheld in the reliability of test-retest measurements between adults and children.

CONCLUSION

Reliable test-retest measurements of the NSI 2.0 can be performed. Consequently, the NSI 2.0 can be applied in clinical practice, in which successive NSI 2.0 scores can be reliably compared and interpreted.

LEARNING OUTCOMES

The reader will be able to describe and discuss both the short-term and long-term test-retest reliability of the Nasality Severity Index 2.0, a new multiparametric approach to hypernasality, and its parameters. Based on this information, the NSI 2.0 can be applied in clinical practice, in which successive NSI 2.0 scores, e.g. before and after surgery or speech therapy, can be compared and interpreted.