# The Relationship Between Vortices, Acoustics, and Vibration in Vocal Fold Asymmetries

> **NIH NIH R01** · UNIVERSITY OF CINCINNATI · 2024 · $638,373

## Abstract

Project summary.
Common operations for unilateral vocal fold paralysis (UVFP), such as Thyroplasty Type 1,
improve vocal efficiency (VE) by closing the membranous gap between the normal and
paralyzed fold. VE measures the degree to which subglottal aerodynamic power is translated to
acoustic power. However, even after surgical treatment, some patients report symptoms such
as vocal fatigue, decreased projection, and decreased intelligibility in noisy environments.
These recalcitrant symptoms will be associated with reduced VE relative to normal voice,
suggesting that enhancing VE could further ameliorate these symptoms. Our previous work in
the excised canine larynx suggests that this further improvement is possible by certain
modifications to the procedure. For example, we found the surprising result that medialization of
the tissue below the fold (infraglottal region) results in higher VE than medialization of the fold
itself (glottal) even though both operations close the medial-lateral membranous gap.
Additionally, inclusion of arytenoid adduction increased VE relative to infraglottal medialization
alone. However, to translate these surgical findings in animals to patients requires a deeper
understanding about how and why various treatment modifications affect VE. In prior work we
found that rotational motion (vortices) occur between the folds during closing. These vortices
produce negative pressures that cause the folds to close together faster, which increase
acoustic intensity and VE. We know that the bottom part of the folds is stiffer than the upper
part; this is referred to as the vertical stiffness gradient (VSG). We have also found that lower
VSG produces weaker vortices and decreased VE. In the first aim, we will further examine the
effect of the VSG on VE. In the second and third aim, we will look at how and why different
treatments for UVFP affect VE. This application lays the foundation for using VE clinically, and
for optimizing clinical treatments for UVFP.

## Key facts

- **NIH application ID:** 10814833
- **Project number:** 5R01DC009435-14
- **Recipient organization:** UNIVERSITY OF CINCINNATI
- **Principal Investigator:** Liran Oren
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $638,373
- **Award type:** 5
- **Project period:** 2009-09-18 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10814833

## Citation

> US National Institutes of Health, RePORTER application 10814833, The Relationship Between Vortices, Acoustics, and Vibration in Vocal Fold Asymmetries (5R01DC009435-14). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10814833. Licensed CC0.

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