Contribution of laryngeal size to differences between male and female voice production

Voice Disorder Prevalence and Vocal Health Characteristics in Children

Importance

Voice disorders impede communication and limit quality of life for many children. However, research demonstrating the prevalence of pediatric voice problems and associated voice use patterns is scarce. This investigation examined the prevalence of voice problems and vocal health characteristics of school-aged children.

Objective

To examine the prevalence of voice problems in school-aged children throughout the US with reference to lifestyle, demographic characteristics, and voice use patterns.

Design, Setting, and Participants

This study used a cross-sectional design to survey a probability sample of caregivers of children aged 4 to 12 years living throughout the US in 2023.

Main Outcomes and Measures

Caregivers were surveyed regarding their children's voice use, voice symptoms, voice problems, extracurricular activities, and demographic information. Caregivers also competed the Pediatric Voice-Related Quality of Life questionnaire. The Fisher exact test, χ2 tests, and logistic regression were used to compare children with and without voice problems.

Results

Overall, 6293 panelists were invited to complete screening questions for the survey, and 1789 individuals were screened for eligibility between March and April 2023. Of these, 1175 parents (65.7%) completed the survey. Twenty-one (1.8%) were excluded for a combination of either high refusal rates (n = 16), speeding (n = 2), or straight lining (n = 12). The final number of participants included in analysis was 1154 caregivers of children aged 4 to 12 years (559 female children [48.4%]; 595 male children [51.6%]; mean [SD] age, 8.02 [2.49] years). The prevalence of voice problems in children was 6.7% (n = 78), and the lifetime prevalence was 12% (n = 138). Benign vocal fold lesions was the most common diagnosis underlying voice complaints, and other causes included respiratory illness, allergies, autism-related voice issues, and other neurological conditions. Risk factors for pediatric voice problems included being male (odds ratio [OR], 1.47; 95% CI, 1.0-2.1), having more than 4 individuals living in the household (OR, 2.30; 95% CI, 1.2-4.4), poor speech intelligibility (OR, 2.26; 95% CI, 1.2-4.3), maternal history of voice problems (OR, 4.54; 95% CI, 1.2-16.4), participating in online gaming (OR, 1.56; 95% CI, 1.0-2.3), and secondhand smoke exposure (OR, 1.7; 95% CI, 1.1-2.6). Voice use-related risk factors included frequent talking, coughing, throat clearing, tantrums/crying, and vocal strain. Voice problems were associated with substantially detracted quality of life as measured by the Pediatric Voice-Related Quality of Life questionnaire, limited social/extracurricular interactions, increased school absences, and negative attention from adults.

Conclusions

The results of this survey study suggest that pediatric voice problems are relatively common and detract from quality of life. Specific environmental and behaviorial factors are associated with increased risk for voice disorders.

Restraining vocal fold vertical motion reduces source-filter interaction in a two-mass model

Previous experimental studies suggested that restraining the vocal fold vertical motion may reduce the coupling strength between the voice source and vocal tract. In this study, the effects of vocal fold vertical motion on source-filter interaction were systematically examined in a two-dimensional two-mass model coupled to a compressible flow simulation. The results showed that when allowed to move vertically, the vocal folds exhibited subharmonic vibration due to entrainment to the first vocal tract acoustic resonance. Restraining the vertical motion suppressed this entrainment. This indicates that the vertical mobility of the vocal folds may play a role in regulating source-filter interaction.

Histologic Examination of Vocal Fold Mucosal Wave and Vibration

OBJECTIVES

Despite gross anatomic and histologic differences between human and canine vocal folds, similar wave patterns have been described yet not fully characterized. We reconstructed vocal fold (VF) vibration in a canine hemilarynx and performed histologic examination of the same vocal fold. We demonstrate comparable wave patterns while exploring the importance of certain anatomic architectures.

METHODS

An in vivo canine hemilarynx was phonated against a glass prism at low and high muscle activation conditions. Vibration was captured using high-speed video, and trajectories of VF medial surface tattooed landmarks were 3D-reconstructed. The method of empirical eigenfunctions was used to capture the essential dynamics of vibratory movement. Histologic examination of the hemilarynx was performed.

RESULTS

Oscillation patterns were highly similar between the in vivo canine and previous reports of ex vivo human models. The two most dominant eigenfunctions comprised over 90% of total variance of movement, representing opening/closing and convergent/divergent movement patterns, respectively. We demonstrate a vertical phase difference during the glottal cycle. The time delay between the inferior and superior VF was greater during opening than closing for both activation conditions. Histological examination of canine VF showed not only a thicker lamina propria layer superiorly but also a distinct pattern of thyroarytenoid muscle fibers and fascicles as described in human studies.

CONCLUSIONS

Histologic and vibratory examination of the canine vocal fold demonstrated human vocal fold vibratory patterns despite certain microstructural differences. This study suggests that the multilayered lamina propria may not be fundamental to vibratory patterns necessary for human-like voice production.

LEVEL OF EVIDENCE

NA (Basic science study) Laryngoscope, 134:264-271, 2024.

Modification of Wendler Glottoplasty for Male to Female Gender Transition

INTRODUCTION

Transgenderism is a condition regarding the gender identity of an individual where their psychological gender is discordant with their anatomic gender. For patients transitioning from Male to Female, voice changes are created predominantly with voice therapy, with vocal surgery as an adjunct if the patient desires it. A common surgical technique is the Wendler Glottoplasty. A CO₂ laser is used to de-epithelialize the anterior third of the vocal folds and the anterior one-third of the folds are sutured together. This shortens the vibratory folds and increases the fundamental frequency (F₀) of the voice. We present a novel modification that incorporates use of injectable aqueous carboxy-methyl-cellulose gel (Prolaryn) to medialize the anterior aspect of the vocal folds and apply fibrin glue sealant (Tisseal) in lieu of sutures, simplifying the operative technique and a thyroarytenoid myectomy for debulking of the cords in select cases.

METHOD

We present ten patients treated with our modified Wendler Glottoplasty technique. Voice assessment was based on F₀ and frequency range pre and post-operatively measured via MDVP and Real-Time Pitch on the Computerized Speech Lab.

RESULTS

The 10 patients had an average age of 34.0 years (range 22.2-64.3 years). The average preoperative F₀ was 136.1 Hz, with an average frequency range of 108.3-282.4 Hz. Postoperatively, the average F₀ was 245.9 Hz, with an average frequency range of 197.3-300.7 Hz. This led to an average F₀ increase of 106.3 Hz.

CONCLUSION

Our modification to the Wendler Glottoplasty successfully resulted in a significant increase in the postoperative F₀. In addition, there was improved satisfaction in vocal character after the procedure, compared to their preoperative vocal character.

Vocal Fold Vertical Thickness in Human Voice Production and Control: A Review

While current voice research often focuses on laryngeal adjustments in a two-dimensional plane from a superior endoscopic view, recent computational simulations showed that vocal control is three-dimensional and the medial surface vertical thickness plays an important role in regulating the glottal closure pattern and the spectral shape of the produced voice. In contrast, while a small glottal gap is required to initiate and sustain phonation, further changes in the glottal gap within this small range have only small effects on glottal closure and spectral shape. Vocal fold stiffness, particularly along the anterior-posterior direction, plays an important role in pitch control but has only a small effect on glottal closure and spectral shape. These results suggest that voice research should pay more attention to medial surface shape in the vertical dimension. Future studies in a large population of both normal speakers and patients are needed to better characterize the three-dimensional medial surface shape, its variability between speakers, changes throughout the life span, and how it is impacted by voice disorders and clinical interventions. The implications for voice pedagogy and clinical intervention are discussed.

Atypical prosodic realization by Mandarin-speaking autistic children: Evidence from tone sandhi and neutral tone

Introduction Atypical prosodic features have been widely reported in autism spectrum disorder (ASD), primarily in non-tonal language speakers. Nevertheless, the prosodic realizations in autistic people who speak tonal languages were relatively understudied. This study aimed to investigate the acoustic and phonetic patterns at the word-level speech in Mandarin-speaking autistic and typically developing (TD) children at different age ranges. Methods Thirty Mandarin-speaking autistic children (15 three- to five-year-olds and 15 six- to eight-year-olds) were recruited into the ASD group. The TD group consisted of 30 age- and gender-matched children. We employed a picture-naming task to elicit the spontaneous speech production of Mandarin disyllabic words in which tone change processes occur, namely Tone 3 (T3) sandhi and neutral tone (T0). Results The phonetic analysis showed that the ASD group generally could produce typical-like T3 sandhi and T0 in terms of pitch height. However, relative to the TD group, they exhibited flatter pitch contours during T3 sandhi production. Moreover, the acoustic pitch mean of citation tones in the ASD group was also significantly higher, accompanied by more rigid pitch curves in contour tones. In addition, the atypical temporal realization in the ASD group was manifested by the longer duration of T0 and the earlier inflection position of T3. Conclusions Mandarin-speaking autistic children under eight had the phonological ability to produce context-dependent tones based on connected tonal information at the word level. Nevertheless, their phonetic prosodic realization of tone change processes was atypical. Our findings provide evidence of atypical prosody in autistic children who speak tone languages. Clinically, these findings may be attributable to underlying neural differences in autistic children.

Phonetic Realizations of Metrical Structure in Tone Languages: Evidence From Chinese Dialects

In tone languages, some case studies showed that the word-level tonal representation was closely related to the underlying metrical pattern. Based on different tonal patterns in prosodic units, the metrical structures could generally be divided into the left- and right-dominant types in Chinese dialects. Yet the cross-dialectal phonetic realizations (e.g., duration and pitch) between or within these two metrical structures were still unrevealed. The current study investigated the duration and pitch realizations of disyllabic prosodic words in Changsha and Chengdu dialects (the left-dominant structure), and in Fuzhou and Xiamen dialects (the right-dominant structure). Results showed that not all the duration patterns across four Chinese dialects were sensitive to different metrical structures, indicating that the duration might not be the universal cue for metrical prominence in Chinese dialects. In terms of pitch realization across all the four Chinese dialects, level tones (sometimes falling tones) generally appeared in the metrically weak unit, while underlying pitch forms appeared in the metrically strong unit. Compared with duration, pitch might be more robust for prosodic realizations of metrical structures in Chinese dialects. Furthermore, there was an interaction between duration and pitch patterns in Chinese dialects, which could shed new light on the phenomenon of “metrical tone sandhi”. Meanwhile, this study also provides some references for the judgment of the metrical stress and prosodic realizations in other Chinese dialects.