Hypernasality and cleft palate speech; a comparison of inter-rater reliability using the temple street scale and a visual analogue scale, in both trained and untrained listeners.

Background: Perceptual listening is considered the ‘gold standard’ in the assessment of speech disorders relating to cleft palate (Kuehn and Molle 2000) but controversy remains as to the most appropriate type of rating scale to use. A descriptive scale for assessing nasality, The Temple Street Scale (TSS), has been tested for validity, reliability and acceptability (Sweeney 2000; Sweeney and Sell, 2008; Sweeney and Fennel 2009) and was subsequently adopted in the Cleft Audit Protocol for Speech–Augmented (John et al 2006). Little research exists for the use of a Visual Analogue Scale but Whitehill (2010) reported good reliability using this scale. Objectives: To compare inter-rater reliability of hypernasality for 10 patients using The Temple Street Scale and a Visual Analogue scal and also to compare inter-rater reliability for both trained and untrained listeners. Methods: Participants (7 trained and 20 untrained) were asked to rate 10 speech samples of varying degrees of hypernasality on two separate occasions. Percentage agreement, Mean Kappa Scores and Intraclass Correlation Coefficients were used to compare the reliability of the two scales and to compare the trained and untrained listener. Results: Examination of percentage agreement showed slightly better agreement for the VAS compared to the TSS, though this was not the case when Mean Kappa was examined. Intraclass Correlation Coefficient showed very good results (> 0.81) for both scales and also showed slightly higher agreement for VAS, in line with Percentage agreement. The untrained listener scored better on both scales with Intrarater results of .984 and .98 for both the VAS and TSS respectfully compared to .937 and .950. Conclusions: No significant difference between the two scales was observed. Both tools showed good reliability with percentage agreement and Intraclass Correlation Coefficients. The ease of use of the VAS may make it a good option for further investigation but interpretation of results for other multi-disciplinary team members difficult. Further research is needed to clarify.