Measuring Speech Perception Using the Wide-Range Acoustic Accuracy Scale: Preliminary Findings

Abstract

Purpose Speech perception requires individuals to hear and differentiate acoustic signals integral to effective communication. Measuring speech perception in children is challenging because speech perception methodology typically requires lengthy experiments that may fatigue children, resulting in limited knowledge of developmental perceptual skills. In this study, we used an adaptive tracking measure along with a wide range of acoustic stimuli to explore how adults, typically developing (TD) children, and children with speech sound disorder (SSD) perceive small acoustic differences in synthetic speech stimuli. Method Twenty-four adults, 15 TD children, and 15 children with SSD between the ages of 7;0–14;0 (years;months) were administered a newly developed perceptual assessment, the Wide-Range Acoustic Accuracy Scale, to determine the just-noticeable difference in discrimination for three separate syllable contrasts. Each syllable contrast varied along a single acoustic parameter: formant transition duration for /bɑ/–/wɑ/, F3 onset frequency for /dɑ/–/ɡɑ/, and F3–F2 distance for /rɑ/–/wɑ/. Results Findings revealed that adults and TD children did not differ in their discrimination of any syllable contrast, but adults significantly differed from SSD children on all syllable contrasts. TD children and children with SSD differed only on the /rɑ/–/wɑ/ contrast. Conclusions Children with SSD demonstrate less accurate and more variable perception skills relative to adults and TD children for /bɑ/–/wɑ/, /dɑ/–/ɡɑ/, and /rɑ/–/wɑ/ syllable contrasts. Clinical implications of the utility of the Wide-Range Acoustic Accuracy Scale are discussed.