Article Text

Download PDFPDF
Regulation of parkinsonian speech volume: the effect of interlocuter distance
  1. Aileen K Hoa,
  2. Robert Iansekb,
  3. John L Bradshawa
  1. aNeuropsychology Research Unit, Psychology Department, Monash University, Clayton 3168, Victoria, Australia, bGeriatric Research Unit, Kingston Centre, Warrigal Road, Cheltenham 3192, Victoria, Australia
  1. Aileen Ho, Department of Psychology, Monash University, Clayton 3168, Victoria, Australia. Telephone 0044 3 9755 5616; fax 0044 3 9905 3948; email Aileen.Ho{at}


This study examined the automatic regulation of speech volume over distance in hypophonic patients with Parkinson’s disease and age and sex matched controls. There were two speech settings; conversation, and the recitation of sequential material (for example, counting). The perception of interlocuter speech volume by patients with Parkinson’s disease and controls over varying distances was also examined, and found to be slightly discrepant. For speech production, it was found that controls significantly increased overall speech volume for conversation relative to that for sequential material. Patients with Parkinson’s disease were unable to achieve this overall increase for conversation, and consistently spoke at a softer volume than controls at all distances (intercept reduction). However, patients were still able to increase volume for greater distances in a similar way to controls for conversation and sequential material, thus showing a normal pattern of volume regulation (slope similarity). It is suggested that speech volume regulation is intact in Parkinson’s disease, but rather the gain is reduced. These findings are reminiscent of skeletal motor control studies in Parkinson’s disease, in which the amplitude of movement is diminished but the relation with another factor is preserved (stride length increases as cadence—that is, stepping rate, increases).

  • Parkinson’s disease
  • speech volume
  • regulation
  • interlocuter distance

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.