Acoustic tracking of articulation errors: [r].

The objective of this study was to determine the usefulness of acoustic tracking as a supplement to perceptual judgements during remediation. One child, receiving weekly individual treatment, participated in a drill-and-practice approach to remediation for a single [w]-for-/r/ substitution error. Imitations of consonant-vowel (CV), VCV, and matched /r/ and /w/ sentence stimuli were audiotape recorded. The temporal and spectral characteristics of the recorded stimuli (i.e., the F2 transition rates and F2 values for the changing [r]) were spectrographically tracked and analyzed over a 70-day remediative period. The acoustic data were compared with the perceptual judgments of articulatory change. Generally, as the child's productions moved from the [w] toward the [r], the measured F2 values became higher and the F2 transition rates lowered. Results suggest that acoustic tracking of a child's productions may become a useful tool to augment perceptual tracking. Implications are discussed for the applications of acoustic tracking within clinical practice.