Acoustic correlates of disordered articulation have been studied and include problemswith timing of vocal onsets and offsets (voicingduring normally voiceless closure intervalsof voiceless stops)27,56 and spirantization (presence of fricative-like, aperiodic noise during stop closures). In another study,57 dysarthricspeakers with IPD showed longer voice onsettimes (VOTs) than normal. Such abnormalVOTs may reflect a problem with movementinitiation,57 which may be related to deficitsin internal cueing, timing, and/or sensory gating.10,58