Background: Auditory-perceptual judgement is commonly used by speech and language therapists (SLTs) to evaluate speech disorders and the results of which are used to guide treatment goal setting. Previous studies have reported significant effect of co-occurring speech disorders (e.g. hypernasality and monotone; hypernasality and articulation disorders) on auditory-perceptual judgements by SLT students. This study further investigates this topic by examining the effect of concurrent articulation and voice disorders on the ratings of severity of each of the disorders in SLT students and SLTs.
Methods: The speech samples were the first two sentences from the Rainbow passage produced by a female speaker who simulated four levels of articulation disorders (typical articulation, and mild, moderate, and severe articulation disorder) at three levels of disordered voice (typical voice, and mild and severe voice disorder), yielding 12 speech sample. Six speech samples were randomly selected and played again during the task to measure intra-rater reliability. The listeners were 20 SLT students and 10 SLTs who used visual analogue scale to rate the severity of articulation disorder and voice disorder for each speech sample in two separate tasks.
Results: Data collection was completed. Mean, standard deviation and range of perceptual ratings for articulation disorder and voice disorder will be obtained for each listener group. A linear mixed effect model will be used to analyse the effect of co-occurring articulation disorder on the perceptual ratings of voice disorder and vice versa. Independent t-test will be used to compare the ratings between the two groups for each of articulation and voice disorders. Intra-class correlation coefficient will be used to assess intra- and inter-rater reliability.
Conclusion: It is hypothesised that the perceptual ratings of articulation disorder will be significantly higher when voice disorder co-occurred; and the same is predicted for the effect of articulation disorder on the ratings of voice disorder.