Several studies have been performed investigating the link between Parkinson's and dysprosody. They have concluded that patients with Parkinson's disease tend to struggle with specific areas of prosody; they are less able to produce the loudness, pitch, and rhythm patterns required for expressing certain emotions, such as anger. In general, the voice modulations needed to express strong emotions are particularly difficult for patients with Parkinson's disease. Abnormal pauses in speech are also a characteristic of Parkinsonian dysprosody, including both pauses in general speech and intra-word pauses. A decrease in speech rate can also be observed in Parkinson's patients.