Can the Lombard effect be used to improve low voice intensity in Parkinson's disease?

Low voice intensity is a common problem in Parkinson's disease. It is typically resistant to drug therapy and often persists despite extensive behavioural speech and language therapy. Based on previous findings that masking noise will produce a consistent increase in voice intensity in most normal individuals, the effects of white masking noise, presented at a sound pressure level of 90 dB, was examined in 10 parkinsonian patients with low voice intensity. Results indicated that all Parkinson's disease patients showed a marked increase in their voice intensity. Given this finding, it is proposed that masking noise may be an effective treatment for reduced voice intensity in parkinsonian speakers, particularly with the future adaptation of portable voice-activated maskers, such as the Edinburgh Masker.