Many people with Parkinson’s have voice problems. The reason for this is due to the fact that the condition causes the muscle tone to change which impacts the muscles you need for speech. 

Soft speech or hypophonia is one of the most common kinds of these speech problems. Some patients may also have difficulties distinguishing between questions and answers. You may hear them speaking in a monotone voice and not realize that they’re speaking loudly. As Parkinson’s advances, people often find it harder to understand what the patient is saying.