Does the type of cleft have an impact on language results? Validation of the Nasalance test in French.

Abstract

Objectives: The nasometer is the most widely used tool for objective assessment of phonation in both research and clinical practice. French standards have been validated in cases of total cleft lip and palate. The objective of this research is to propose a second validation study on velopalatal clefts. The 15 most sensitive and specific items from the initial validation were selected to create a test that is suitable for use in a clinical setting. A secondary objective is to ascertain the impact of cleft type on nasometry.

Methods: A total of 39 participants with an isolated or non-isolated velopalatal cleft were recruited for the study. A speech therapist conducted a blinded subjective evaluation of phonation. The nasometric assessment was based on a corpus developed in collaboration with the CNRS Phonetics and Phonology Laboratory. The corpus is composed of items that are phonetically balanced.

Results: The obtained nasalance threshold values ranged from 11 to 40%. The study corroborated the existence of a voicing effect, whereby the articulation of voiced consonants was associated with a higher nasalance score. This effect, not previously observed in other studies, is specific to French phonetics. Participants with a velopalatal cleft exhibited higher nasalance scores compared to those with a total cleft.

Conclusion: By validating the most relevant stimuli, a French Nasalance Test can be established. With a view to harmonising assessment protocols, it would be appropriate to use the items from this test in subjective assessment.