[Correlations between vocal qualities and mental retardation].

This research is intended to verify the existence of vocal spectrographic alterations, with particular reference to the values of Fundamental Frequency, in patients with different levels of Mental Retardation. The results show the existence of a direct correspondence between the values of the Fundamental Frequency and the level of Mental Retardation: the spectrographic characteristics appear to be more altered in subjects with severe Mental Retardation. The spectrographics patterns are characterized by the presence of bi-phonation particularly at the onset time and at the end, and by a noise signal on constant frequency. The shifts of Fundamental Frequency and voice breakage are rarely detected.