Contracted Extravelar Segments of the Levator Veli Palatini Muscle: A Magnetic Resonance Imaging Morphometric Study.

OBJECTIVES: To provide detailed descriptions of contraction-induced morphometric changes in the extravelar segments of the levator veli palatini (LVP) muscle using 3-dimensional (3-D) magnetic resonance imaging (MRI). DESIGN: Three-dimensional MRI data were acquired at rest and during "silent /i/" from 4 singers. During silent /i/, participants voluntarily sustained velar elevation while breathing orally for the entire scan time. Focusing on the extravelar segments, LVP length, angle of the muscle origin, and cross-sectional area (CSA), measurements were obtained and compared between tasks. RESULTS: Three of the 4 participants exhibited the expected patterns of change following concentric contraction of the LVP muscle. Consistent changes from the resting to the contracted state included reductions in LVP length by 13.5% and angle of the muscle origin by 9.8%, as well as increases in CSAs by 22.1%, on average. CONCLUSIONS: This study presented high-resolution data of the LVP muscle behavior with the first in vivo 3-D measurements of the contracted LVP muscle, which can be useful for the validation of computational models that aim at describing biomechanical properties of the LVP muscle in future research. The active behavior of the extravelar LVP muscle also provides some insight on optimal LVP muscle geometry to consider during cleft palate repair.

Connecting Auditory-Perceptual Prompts Used in Voice Therapy to Anatomy and Physiology: Application to the Estill Voice Model and the Rehabilitation Treatment Specification System.

PURPOSE: This clinical tutorial will present the concept of applying auditory-perceptual prompts (implicit instruction) typically used in voice therapy to the anatomy and physiology of the voice production system (explicit instruction) via the Estill Voice Model (EVM) and the Rehabilitation Treatment Specification System (RTSS). METHODS: EVM offers an integrated implicit-explicit instructional approach to voice training allowing for isolated practice of vocal structures (explicit) that interact to produce functional voice qualities (implicit), such as modal speech and louder projected voice qualities. In EVM, voice quality is correlated with the specific anatomy and physiologic adjustments via 13 Estill Figures and Options (eg, Larynx Figure has three options: High, Mid, and Low). RTSS provides a framework to connect client change in functioning (ie, target) with clinician action (ie, ingredients). Mechanisms of action connect the target to the ingredients by hypothesizing how the treatment is expected to work. RESULTS: Evidence is provided for connecting auditory-perpetual voice prompts with the anatomy and physiology of voice and supporting an integrated implicit-explicit approach to voice therapy. The concept of linking commonly used implicit auditory-perceptual prompts used in voice therapy (eg, humming, loud "aahh") to explicit anatomy and physiology training (eg, 13 Estill Figures and Options) is demonstrated using EVM and the RTSS framework with case studies and video examples. CONCLUSIONS: Clinicians may choose to use anatomy and physiology of voice to define and provide explicit instruction for typically used implicit auditory-perceptual prompts. Future research is warranted to test the concept applied to voice therapy models in the literature across prevention and treatment of voice disorders.

Oropharyngeal and Aryepiglottic Narrowing for Twang: A Magnetic Resonance Imaging Study.

OBJECTIVE: This study aimed to compare vocal tract configurations between speech and twang qualities. METHODS: Magnetic resonance imaging data were acquired from five professional vocalists while producing the sustained vowel /i/. Width and area measurements were obtained from the axial (ie, transverse) images to evaluate oropharyngeal narrowing and aryepiglottic (AES) narrowing. RESULTS: Four out of five participants exhibited a smaller vocal tract area for twang than for speech at the oropharyngeal level, with the extent of narrowing ranging from 18.8% to 49.6%. Only one participant showed a meaningful decrease in oropharyngeal anteroposterior (AP) width, while three participants showed meaningful decreases in oropharyngeal mediolateral (ML) width for twang compared to speech. At the AES level, all participants showed a smaller vocal tract area for twang than for speech, with the extent of narrowing ranging from 11.8% to 52.4%. Two participants exhibited meaningful decreases in AES AP width, while three participants showed meaningful decreases in AES ML width for twang compared to speech. CONCLUSIONS: Axial imaging revealed oropharyngeal and AES narrowing associated with twang, more prominent in the ML than the AP dimension. Notable individual variations in the mechanism and degree of narrowing at the oropharyngeal and AES levels were observed. The degree of narrowing varied among participants, highlighting the complexity of physiological maneuvers involved in twang production. Future research is necessary to identify broader patterns in twang production for effective pedagogic and therapeutic applications.

The Role of Instructions in Motor Learning of Oral Versus Nasalized Speech Targets.

PURPOSE: The purpose of this study was to investigate how general, implicit instructions with auditory-perceptual emphasis; specific, explicit instructions with biomechanical focus; or both affect learning of oral-nasal balance control in speech. METHOD: Thirty healthy, vocally untrained participants were assigned to one of three instructional groups (i.e., implicit, explicit, and integrated) and learned to produce oral versus nasalized vowel-, syllable-, and phrase-level targets during once-weekly sessions over 4 weeks. Learning gains and performance variability were analyzed using nasometry. RESULTS: We observed a significant main effect of instruction type on learning gains at phrase level (p = .016). Specifically, the integrated group (M = 59.8%) significantly outperformed the explicit group (M = 37.9%) and numerically outperformed the implicit group (M = 45.1%). For nasalized phrase targets, results revealed a significant main effect of instruction type on performance variability (p = .042), but pairwise comparisons between instruction groups were not significant. CONCLUSIONS: The integration of implicit processes via auditory-perceptual modeling and explicit processes via relevant biomechanical directives resulted in larger motor learning gains, especially at higher levels of task complexity (i.e., phrase) compared to providing implicit or explicit instruction alone. The higher performance variability (i.e., less stable productions) that was sometimes induced by explicit instruction did not negatively impact learning when integrated with implicit instruction. Clinical implications for speech/voice therapy models are discussed.

Histologic Investigation of the Salpingopharyngeus.

PURPOSE: The purpose of this study was to characterize the histologic contents of the salpingopharyngeal fold. The primary objective was to observe the presence of salpingopharyngeus (SP) muscle fibers, particularly at the section near the muscle origin at the torus tubarius (TT). METHOD: Histologic samples of the salpingopharyngeal fold from 10 cadavers (six females and four males) were analyzed. Following a head bisection, a tissue sample measuring 5 mm in length along the course of the salpingopharyngeal fold was collected from one side (i.e., right or left). The tissue sample was taken from the estimated base of the TT to a point 5 mm inferiorly. Slides were prepared using a standard histological approach and basic pathological staining and analyzed via bright-field microscopy. RESULTS: Skeletal muscle fibers were identified in eight of the 10 tissue blocks of the salpingopharyngeal fold, with dense connective tissue identified in the remaining two tissue blocks. Glandular material was also identified in all 10 tissue blocks. CONCLUSIONS: Skeletal muscle fibers and/or dense connective tissue can be consistently identified in the section of the salpingopharyngeal fold near the TT. Glandular material is also consistently present in this same region of the salpingopharyngeal fold. These findings are discussed in relation to possible functional roles of the salpingopharyngeal fold contents, including the SP muscle.

A pilot investigation of twang quality using magnetic resonance imaging.

BACKGROUND: Twang quality is a bright, piercing quality often produced in contemporary pop/rock/country music, musical theatre singing, and character voices. Despite its potential application to voice therapy and singing pedagogy, limited information is available regarding the exact physiologic underpinnings of twang quality. The purpose of this study was to provide quantitative information regarding three-dimensional (3D) vocal tract configurations of twang quality using magnetic resonance imaging (MRI). METHODS: Two participants, with professional singing and pedagogy experience in a variety of singing styles, sustained twang and speech quality on vowel /i/ while lying supine in the MRI scanner. Vocal tract measures included larynx height and velar height in the midsagittal view as well as lateral pharyngeal width, anteroposterior pharyngeal (AP) width, and pharyngeal area in the axial view. RESULTS: When compared to speech /i/, participants produced twang with a smaller pharyngeal area with significant narrowing in the lateral dimension, a slightly elevated laryngeal position, and closed VP port. Of note, Participant 1 also demonstrated significant pharyngeal narrowing in the AP dimension at the oropharyngeal level. CONCLUSION: The results are consistent with some aspects of previous descriptions of twang but provide further clarification regarding physiologic underpinnings of twang quality for therapeutic and pedagogic application.

A Cadaveric and Magnetic Resonance Imaging Investigation of the Salpingopharyngeus.

Purpose The aim of the study was to update our information regarding the salpingopharyngeus (SP) muscle using cadaveric and in vivo magnetic resonance imaging (MRI) data. Primary objectives were to (a) observe the presence/absence of the muscle and (b) quantify and describe its dimensions and course. Method SP specimens from 19 cadavers (10 women, nine men) were analyzed. Following head bisection, measurements of SP, including width of the cartilaginous attachment (CW) and width of the superior muscle base (SMW), were taken before and after removal of the overlying mucosa. In addition, SP was analyzed in 15 healthy subjects (eight men, seven women) using high-resolution three-dimensional MRI data. CW and SMW measures were replicated in the paraxial MRI view. Results The presence of the salpingopharyngeal fold and muscle was confirmed bilaterally in all cadaveric and living subjects. Following mucosa removal, mean cadaveric CW and SMW measurements were 5.6 and 3.8 mm, respectively. Mean in vivo CW and SMW were 6.1 and 3.7 mm, respectively. Results from the hierarchical regression analyses revealed that, in both cadaveric and living groups, SMW is dependent on the relationship between age and body weight, after controlling for sex. Conclusions The salpingopharyngeal fold and SP muscle are always present bilaterally and can be quantified at the superior origin using both cadaveric and in vivo three-dimensional MRI data. Though both the superior origin and inferior course of SP are highly variable, the size of the SP muscle is dependent on characteristics known to affect muscle fibers, such as the relationship between age and body weight. Given the consistent and quantifiable presence of the SP muscle, its potential role in velopharyngeal function for speech and swallowing is reconsidered. Supplemental Material https://doi.org/10.23641/asha.14347859.

Laryngeal resistance distinguished pressed, normal, and breathy voice in vocally untrained females.

The purpose of this study was to determine if pressed, normal, and breathy voice can be distinguished by laryngeal resistance (LR) in vocally untrained females. Twelve adult females, with no vocal expertise or training, produced each of the voice qualities on the pitch A3 (220 Hz) during a repeated consonant-vowel utterance of /pi/ into a Rothenberg vented face-mask with attached microphone, pressure, and air-flow transducers. Results indicated that LR was successful in distinguishing pressed, normal, and breathy voice in vocally untrained females. The results are consistent with previous research and further support the suggestion that LR is a useful measure for studying the co-ordinative interactions across respiratory and laryngeal subsystems of voice production.