Speech Loudness and Quality 12 Months after Intensive Voice Treatment (LSVT®) for Parkinson’s Disease: A Comparison with an Alternative Speech Treatment

Thirty-five individuals with idiopathic Parkinson’s disease were enrolled in speech treatment. Twenty-two were enrolled in a high-effort phonatory-respiratory treatment program (Lee Silverman Voice Treatment, LSVT®) and 13 were enrolled in a high-effort respiratory treatment program (RET). Perceptual judgments of speech loudness and quality were made independently by 6 listeners on recordings of the ‘Rainbow Passage’. These recordings had been obtained just before treatment (pre) and at 12 months’ follow-up (FU12). The speech samples in the LSVT group, but not in the RET group, were significantly more likely to be perceived ‘louder’ and ‘better quality’ at FU12 than at pre (p < 0.0001). These findings, along with others, suggest that the long-term effects of the LSVT are perceptible, clinically significant and treatment-specific.