Acoustic Perturbation Measures Improve with Increasing Vocal Intensity in Individuals With and Without Voice...

Area of Science:

• Speech and Hearing Science
• Acoustic Analysis
• Voice Disorders

Background:

• Acoustic perturbation measures (jitter, shimmer, HNR) are key in voice analysis.
• Vocal loudness variations can influence these measures, potentially confounding results.
• Understanding these influences is vital for accurate voice disorder diagnosis.

Purpose of the Study:

• To investigate the effect of voice sound pressure level (SPL) on acoustic perturbation measures (jitter, shimmer, HNR).
• To compare these effects in adults with voice disorders versus a vocally healthy control group.
• To assess the role of pathology and professional voice use on acoustic measures.

Main Methods:

• A matched case-control study involving 58 female voice patients and 58 healthy controls.
• Participants produced sustained /a/ vowels at soft, comfortable, and loud phonation levels.
• Acoustic voice SPL, jitter, shimmer, and HNR were measured using Praat; statistical analyses included linear mixed models.

Main Results:

• Increased voice SPL significantly decreased jitter and shimmer, and increased HNR in both groups.
• Voice pathology was not directly linked to higher jitter/shimmer, but HNR was higher in patients at comfortable loudness.
• Professional voice use level significantly affected jitter, shimmer, and HNR.

Conclusions:

• The clinical utility of jitter, shimmer, and HNR may be limited without accounting for voice SPL and professional voice use.
• Further research is needed to determine the value of perturbation measures when these factors are controlled.
• Standardizing loudness conditions is essential for reliable acoustic voice analysis.