Respiratory dynamics and speech intelligibility in speakers with generalized dystonia.

This study investigated aspects of respiratory function, during quiet breathing and monologue, in six adult dystonic subjects and compared the findings to a control group of four neurologically intact adults. Additionally, breathing dynamics were compared with speech intelligibility. Respiratory inductive plethysmography was used to assess breathing rate, periodicity of the breathing pattern, and inspiratory lung volume. Ear oximetry was used to assess arterial blood oxygen saturation. Speech intelligibility was rated by a panel of five judges. Breathing patterns differed between groups; the dystonic subjects showed a faster breathing rate, less rhythmic breathing pattern, decreased lung volume, and apnealike periods accompanied by a decrease in arterial blood oxygen saturation. These differences were observed during quiet breathing and monologue. Decreased speech intelligibility was strongly related to differences in breathing dynamics.