Listener Ratings of Stuttering: Evaluating Two Auditory-Perceptual Scales

Area of Science:

• Speech-Language Pathology
• Auditory Perception
• Clinical Assessment

Background:

• Stuttering is a complex motor speech disorder affecting speech fluency, timing, and rhythm.
• Current methods for assessing stuttering in research and clinical settings lack consistent reliability and efficiency.
• Objective and subjective measures are crucial for understanding and managing stuttering.

Purpose of the Study:

• To compare the validity and reliability of two auditory-perceptual scales for assessing stuttering in adult speakers.
• To evaluate direct magnitude estimation (DME) and equal-appearing interval (EAI) scales.
• To determine the most effective scaling procedure for capturing stuttering severity.

Main Methods:

• Two experiments were conducted using unfamiliar listener ratings of speech samples from adults who stutter.
• Listeners utilized either a DME or a 7-point EAI scale to rate stuttering severity.
• Experiments varied sample characteristics (syllable count vs. duration) and rater training (predefined severity vs. self-defined severity).

Main Results:

• Both rating scales demonstrated appropriateness for assessing stuttering.
• The 7-point EAI scale proved valid in capturing unfamiliar listeners' perception of stuttering severity.
• Findings suggest EAI scales are a reliable tool for auditory-perceptual assessment of stuttering.

Conclusions:

• The 7-point equal-appearing interval scale is a valid and reliable method for assessing stuttering severity based on unfamiliar listener perception.
• Further research is needed to establish optimal rater numbers for stable ratings and the utility of average vs. single ratings for clinical change.
• These findings contribute to improved assessment protocols for stuttering in clinical and research contexts.