The establishment of phonological contrast between fricatives by children with phonological disorder: manipulation of acoustic cues

Abstract

The present study focuses on the presence of covert contrasts in the speech of children with phonological disorder. The hypothesis is that children with phonological disorders manipulate secondary acoustic cues in an attempt to distinguish the phonological contrasts. There were used five audio recordings of speeches from five children with speech disorder between 4 and 5 years old, who presented the so-called “phonic substitution” involving the sound class of the fricatives. The software PRAAT was select for the edition and analysis of the data. A phonetic transcription of the first repetition of each child were performed by three judges and considered the agreement of 66%. From this transcription, we carried out with the contrastive phonological analysis of the production of the five children and, finally, we performed the acoustic analysis of all the “substitutions” based on six parameters. We could verify the existence of covert contrast in the productions as homophones aurally taken by the judges, representing a total of 54% of total substitutions identified through impressionistic approach by the judges. Children with phonological disorder are preferably anchored in secondary acoustic cues in an effort to distinguish between fricatives phones. The data obtained in this study allow us to reflect on the importance of considering the phonetic detail within the phonological models.