Development and Validation of a Single-Variable Comparison Stimulus for Matching Strained Voice Quality Using a...

Area of Science:

• Speech Science
• Acoustic Phonetics
• Voice Quality Analysis

Background:

• Accurate acoustic and perceptual quantification of vocal strain remains a significant challenge in voice research.
• Previous methods for assessing voice qualities like breathiness and roughness have been established.
• A need exists for a more rigorous and reliable method to measure vocal strain.

Purpose of the Study:

• To develop and validate a single-variable matching stimulus (SVMT) for the accurate measurement of vocal strain.
• To enhance the rigor of vocal strain quantification through a standardized measurement approach.
• To establish a reliable method for assessing perceived vocal strain.

Main Methods:

• Synthesized 21 comparison stimuli using a speech-shaped sawtooth waveform and noise, manipulating bandpass filter gain to vary computed sharpness.
• Assessed 10 natural /ɑ/ vocal stimuli with varying degrees of strain using the SVMT.
• Utilized perceptual magnitude estimation (ME) to evaluate both natural and synthetic stimuli.

Main Results:

• Magnitude estimation data confirmed the synthetic stimuli accurately represented varying levels of perceived strain.
• Perceived strain magnitudes showed a significant and linear increase with computed sharpness (R² = .99).
• Strain matching values were strongly predicted by computed sharpness (R² = .96) and perceived strain magnitudes (R² = .95).

Conclusions:

• Perception of vocal strain is closely linked to computed sharpness.
• The single-variable matching task (SVMT), using bandpass filter gain as the independent variable, accurately and precisely captures vocal strain.
• This validated method offers a more rigorous approach to vocal strain quantification.