Related Experiment Video
Updated: Mar 18, 2026

A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis ALS
Published on: February 21, 2011
[Acoustic analysis in patients with unilateral arytenoid dislocation and unilateral vocal fold paralysis]
Objective:
To analysis the acoustic characteristics in patients with unilateral arytenoid dislocation and unilateral vocal fold paralysis, and evaluate the application value of acoustic analysis technique in these two diseases.
Method:
The voice signals of sustained vowel /a/ were measured using the software MDVP in 50 healthy adults and 67 patients with unilateral vocal cord movement disorders. The acoustic parameters (jitter, shimmer, NHR and F₀) were analyzed. All patients were divided into arytenoid dislocation group (36 cases) and vocal fold paralysis group (31 cases) through the laryngeal electromyography. All groups were divided into male and female group again. The acoustic characteristics between the two experimental groups and normal control groups were observed and compared. Results were analyzed using Rank sum test.
Result:
(1) In both male or female groups, there were significant differences in jitter and shimmer between two experimental group and control group. In both male or female groups, there were significant differences in NHR between arytenoid dislocation group and control group. There were no significant differences in NHR between vocal fold paralysis group and control group. Except for the male vocal fold paralysis group, there were significant differences in F between the other experimental groups and control groups. (2) In both male or female groups, there were no significant differences in jitter and shimmer between vocal fold paralysis group and arytenoid dislocation group. There were significant differences in NHR.
Conclusion:
The acoustic parameters are effective parameters to measure the voice quality of patients with unilateral arytenoid dislocation and unilateral vocal fold paralysis. NHR is the most sensitive parameter in the distinction of vocal cord paralysis and arytenoid dislocation.
Related Concept Videos
Larynx
Anatomy of the Larynx
The larynx consists of various components, including cartilage, muscles, and vocal cords. Its structure includes three large unpaired cartilages—the thyroid, cricoid, and epiglottis—and three smaller paired cartilages—the arytenoids,...
Respiratory System Abnormal Finding II: Palpation and Auscultation
Palpation Findings
During a respiratory assessment, palpation can reveal several vital abnormalities:
Physical Assessment of the Respiratory Tract IV: Auscultation
Breath Sounds
Breath sounds are categorized into vesicular, bronchovesicular, and bronchial.
Physical Assessment of the Respiratory Tract II: Palpation
Thoracic Palpation
Thoracic palpation detects tenderness, masses, lesions, respiratory excursions, and vocal fremitus. The nurse assesses...
Physical Assessment of the Respiratory Tract III: Percussion
Percussion in Respiratory Assessment
Percussion evaluates underlying tissue composition with audible and tactile vibrations,...

