Fundamental frequency perturbation observed in sustained phonation.

Area of Science:

• Speech Science
• Acoustic Phonetics
• Voice Production

Background:

• Cycle-to-cycle frequency perturbation, known as jitter, is a key acoustic measure of voice quality.
• Understanding how jitter varies with fundamental frequency (fo) is crucial for voice analysis and diagnostics.
• Previous research has explored vocal jitter, but its relationship with fundamental frequency requires further detailed examination.

Purpose of the Study:

• To investigate the relationship between fundamental frequency (fo) and cycle-to-cycle frequency perturbation (jitter) in sustained vowel phonations.
• To analyze how jitter magnitude and jitter ratio change across a range of fundamental frequencies in adult male voices.

Main Methods:

• Sustained /i/ vowel phonations from six adult males were recorded.
• Voice samples were analyzed using a peak-picking fundamental frequency (fo) analysis program.
• Cycle-to-cycle frequency perturbation (jitter) was quantified across a fundamental frequency range of 98 Hz to 298 Hz.

Main Results:

• Between 98 Hz and 210 Hz, mean jitter size decreased as fundamental frequency (fo) increased, while jitter ratios remained stable.
• Above approximately 210 Hz, mean jitter size remained relatively constant, leading to an increase in the jitter ratio with rising fo.
• The study highlights distinct patterns of jitter behavior at different fundamental frequency ranges.

Conclusions:

• The findings demonstrate a frequency-dependent relationship between fundamental frequency (fo) and vocal jitter.
• Jitter ratio increases at higher fundamental frequencies, suggesting potential implications for voice health assessment.
• Further research is needed to explore temporal resolution, vowel-specific characteristics, and alternative perturbation measures in voice analysis.