Related Experiment Video
Updated: Nov 21, 2025

A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis ALS
Published on: February 21, 2011
Acoustic parameters for the evaluation of voice quality in patients with voice disorders
Gelin Li1, Qian Hou1, Chi Zhang1
1ENT, Beijing Friendship Hospital affiliated to Capital Medical University, Beijing, China.
Background:
To investigate the value of the standard deviation of the fundamental frequency (F0 SD), jitter, and shimmer for the evaluation of voice quality and the description of vocal characteristics in patients with voice disorders.
Methods:
This prospective cohort study included 4 groups: vocal cord polyps (VCP) group (n=55), early-stage (stage I-II) laryngeal carcinoma (ELC) group (n=35), mutational falsetto (MF) group (n=17), and a normal control group (n=29). The participants were asked to emit a sustained vowel /a/ and raise the pitch gradually. Acoustic parameters, including F0, F0 SD, jitter, and shimmer, were recorded and analyzed.
Results:
The F0 SD was highest in the MF group. The F0 SD in the MF group and the ELC group was significantly higher than that in the VCP group and the control group (P<0.05), and the F0 SD in the VCP group was significantly higher than that in the control group (P<0.05). However, there was no significant difference in F0 SD between the MF group and the ELC group (P>0.05). The jitter and shimmer in the ELC group were significantly higher compared to the other groups (P<0.05), and the jitter and shimmer in the VCP group were significantly higher than those in the MF group and the control group (P<0.05). There were no significant differences in jitter or shimmer between the MF group and the control group (P>0.05).
Conclusions:
F0 SD, jitter, and shimmer are important parameters for the evaluation of pitch variation during sustained phonations, and can discriminate between MF and voice disorders.
Related Concept Videos
Physical Assessment of the Respiratory Tract IV: Auscultation
Breath Sounds
Breath sounds are categorized into vesicular, bronchovesicular, and bronchial.
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:
Assessment of Airway, Skin Color, and Use of Accessory Muscles
Introduction
The initial evaluation of a patient's respiratory system...
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,...

