The effectiveness of traditional methods and altered auditory feedback in improving speech rate and intelligibility in speakers with Parkinson's disease

Communication problems are a frequent symptom for people with Parkinson's disease (PD) which can have a significant impact on their quality-of-life. Deciding on the right management approach can be problematic though, as, with the exception of LSVT, very few studies have been published demonstrating the effectiveness of treatment techniques. The aim of this study was to compare traditional rate reduction methods with altered auditory feedback (AAF) with respect to their effectiveness to reduce speech rate and improve intelligibility in speakers with PD. Ten participants underwent both types of treatments in once weekly sessions for 6 weeks. Outcomes measures were speech rate for passage reading as well as intelligibility on both a passage reading and a monologue task. The results showed that, as a group, there was no significant change in either speech rate or intelligibility resulting from either treatment type. However, individual speakers showed improvements in speech performance as a result of each therapy technique. In most cases, these benefits persisted for at least 6 months post-treatment. Possible reasons for the variable response to treatment, as well as issues to consider when planning to use AAF devices in treatment are discussed.