When communicating, our brains use a combination of auditory feedback (how you hear yourself) and proprioceptive feedback (how your muscles feel when moving) to judge how loud we are speaking. However, in individuals with Parkinson’s Disease, this feedback system is not functioning properly. In result, Parkinson’s research shows that most people perceive their own speech as louder than it actually is. This lack of awareness is not simply “not paying attention” — rather it’s a neurological calibration issue. Brain areas involved in error detection (like the sensory cortex and supplementary motor area) are not supplied with enough dopamine to recognize and adjust the output when the voice is too soft