Some effects of Vowel Space Area (VSA) reduction in speech intelligibility

This study intends to verify the presence of a correlation between the size of vowel space and the speech intelligibility. A reduced intelligibility is a common problem for those individuals suffering from dysarthria. They show a compressed vowel space with an important degree of acoustic centralization. A recent metric employed to distinguish healthy from dysarthric speech is represented by the Vowel Space Area (VSA). We have tested this parameter by comparing subjects with Down Syndrome to control speakers. The results of the present research, the first available data for Italian language, proved that the VSA is a suitable acoustic predictor of an impaired intelligibility.