ABOUT PARKINSON'S DISEASE: This is a degenerative disorder of the central nervous system, first described by English apothecary James Parkinson in 1817. Symptoms include muscle rigidity, tremors, slowing physical movement, and can progress to loss of physical movement. Essentially, the problems are caused by issues with the production and action of dopamine within the brain. It can also cause cognitive problems and many other symptoms. Causes are not typically identified, but can include genetics, toxins, head trauma, and others.
LOMBARD EFFECT: The Lombard Effect is an involuntary phenomenon that occurs when a person speaking must overcome background noise in order to be heard. People will alter the pitch, volume, and length of syllables in order to make speech more easily understood. The phenomenon even happens in non-human animals. The shifting enables the audience to perceive the speech more clearly in a loud environment.
The Acoustical Society of America contributed to the information contained in the TV portion of this report.