I just came across this very interesting page by the Auditory Neuroscience Laboratory at the Northwestern University’s School of Communication. They write:
Musical experience has a pervasive effect on the nervous system. Our recent articles show that lifelong musical experience enhances neural encoding of speech as well as music, and heightens audiovisual interaction. Our work suggests that musicians have a specialized neural system for processing sight and sound in the brainstem, the neural gateway to the brain. This evolutionarily ancient part of the brain was previously thought to be relatively unmalleable; however, our studies indicate that music, a high-order cognitive process, affects automatic processing that occurs early in the processing stream, and fundamentally shapes subcortical sensory circuitry.
The site includes links to scientific publications on topics such as music experience and brain plasticity, music and speech, and music and auditory and audiovisual processing. Here is the link to the site: