Multiple phonetically trained-listener comparisons of speech before and after articulatory intervention in two children with repaired submucous cleft palate

Abstract

In Cleft Palate (CP) assessments based on phonetic transcription are the gold standard- therapy outcome measure, despite reliability difficulties. Here we propose a novel perceptual evaluation, applied to ultrasound-visual biofeedback (U-VBF) therapy and therapy using visual articulatory models (VAMs) for two children with repaired submucous CP. Three comparisons were made: post VAM, post U-VBF and overall pre- and post-therapy. Twenty-two phonetically-trained listeners were asked to determine whether pre- or post-therapy recordings sounded closer to the English target-, using their own implicit stored knowledge (prompted via orthographic representation) as a comparison. Results are compared with segment-oriented percent target consonant correct (PTCC) derived from phonetic transcriptions by the authors. Listener judgements and PTCC suggest that both children made improvements using both VAM and U-VBF. Statistical analysis showed listener agreement across all three comparisons, despite agreement being poor. This perceptual evaluation offers a straightforward method of evaluating the effectiveness of interventions and can be used by phonetically trained or lay listeners.