# Optimization And Therapeutic Translation of Semi-Occluded Vocal Tract Techniques.

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 2020 · $325,125

## Abstract

Project Summary
Semi-occluded vocal tract (SOVT) therapy is widely used to treat various voice disorders, including vocal fold
lesions and primary muscle tension dysphonia. The mechanism of SOVT therapy has not been thoroughly
studied. The added vocal tract, which is often a straw, changes both supraglottal acoustic impedance, and
static supraglottal pressure; however, how these parameters independently contribute to the voice therapy
have not been clarified. We would like to observe the supraglottal effects as well as the acoustic impedance
effects of phonation independently and quantitatively. Our long-term aim is to improve upon current methods of
SOVT therapy by exploring the underlying mechanisms and finding the optimal SOVT configurations that allow
for the greatest increase in best quality of phonation. The proposed research consists of two independent
phases.
During Phase I, an excised canine larynx model will be used for the independent scientific evaluation and
optimization of three variables in SOVT therapy – (1) length of vocal tract extension, (2) vocal tract outlet
constriction, and (3) regulated supraglottal pressure input. Extending the length and constricting the outlet of
the vocal tract increases the acoustic impedance which then increases supraglottal pressure and the ease of
phonation. The use of a regulated pressure input is a novel addition to SOVT therapy, which allows the
supraglottal pressure to be directly controlled. Wide ranges of each SOVT variable will be examined
individually to determine the optimal levels of each modification. Vocal phonation will be systematically
monitored through dependent aerodynamic, electroglottographic, and acoustic parameters, including vocal
efficiency.
During Phase II, in human subjects, we will independently assess the three variables of SOVT therapy on
subjects with and without hyperfunctional voice disorders. The results from the studies using an ex-vivo model
gives information based solely on the mechanism, with an unscaled pattern; whereas, Phase II studies will give
insight into the dynamic and behavioral reactions present in human subjects. Effects on vocal economy will be
evaluated using aerodynamic, electroglottographic, and acoustic parameters as dependent variables. Through
a standardized therapeutic task, the effect of the modifications of SOVT therapy can be isolated. The studies
outlined in this proposal will evaluate optimal SOVT therapy configurations through independently testing the
three SOVT modifications. Further, we also will include long and short duration therapeutic tasks. By testing
each modification across different task durations, we can identify the minimal task duration to achieve
significant benefits. Monitoring the immediate and long-term effects allows further insight on the overall impact
that this voice therapy can have.

## Key facts

- **NIH application ID:** 9850953
- **Project number:** 5R01DC015906-03
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Jack J Jiang
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $325,125
- **Award type:** 5
- **Project period:** 2018-02-05 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9850953

## Citation

> US National Institutes of Health, RePORTER application 9850953, Optimization And Therapeutic Translation of Semi-Occluded Vocal Tract Techniques. (5R01DC015906-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9850953. Licensed CC0.

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