Changes in vocal loudness following intensive voice treatment (LSVT (R)) in individuals with Parkinson's disease: A comparison with untreated patients and normal age-matched controls

This study assessed the impact of the Lee Silverman Voice Treatment (LSVT(R )) on vocal loudness [sound pressure level (SPL)] in a group of dysarthric individuals with idiopathic Parkinson's disease (IPD). Pre- to post-treatme nt changes in SPL in the treated group were compared with changes in voice SPL during the same time in two control groups: individuals with IPD not tr eated with the LSVT(R) and in non-disordered individuals. ape-matched to th e patients. All subjects produced the same voice and speech tasks-sustainin g vowel phonation. reading the "Rainbow Passage," producing a short monolog ue, and describing a picture. These tasks were recorded at three different occasions: just prior to treatment. just after treatment, and 6 months foll owing treatment. The individuals treated with LSVT(R) increased voice SPL f rom baseline to post-treatment by an average of 8 dB and from baseline to 6 months follow-up by an average of 6 dB. These changes were statistically s ignificant and perceptibly audible. No significant changes in SPL were obse rved in the control groups during the time corresponding to the treatment a nd follow-up. Differences in SPL between the treated and untreated patients at post-treatment and follow-up were statistically significant for all voi ce and speech tasks. These findings, along with others, provide additional support for the efficacy of the LSVT(R).