Progressive supranuclear palsy: longitudinal study by acoustical analysis of speech

The aim of this study is to measure objectively and quantitatively different speech parameters in PSP for four years. The present investigation performed an acoustic analysis of sustained vowel phonation /a/, maximum phonatory time, numbers sentence (1,2,3,4) and rapid syllable repetition (/pa/, /ta/, /ka/ and /pataka/). Various parameters were considered: F0, intensity, formants, shimmer, jitter, hannonic-to-noise ratio (NHR), the mean number of syllables, the median syllable duration, voice onset time (VOT), speech rate, silence rate and prosodic elements. Alterations in voice and speech evolve towards articulatory imprecision, poor vocal quality, reduced TMF, reduced speech rate, decreased intonation variability and prolonged pauses in diadochokinesia. This analysis revealed a coincidence in time between progressive global speech impairment and highly percentage of incomplete clousures in VOT, with progressive dysphagia.