Those neurochemical things are typically talked about in too superficial ways, and to talk about them in more satisfactory ways, we'd be talking about a lot more than what people typically talk about. The topics would blow up. In other words, it's not advisable to hinge any model of self-understanding on those things, and it's definitely not advisable to start thinking in terms of self-diagnosing or self-medication, based on the superficial ways of talking about those things. Absolutely _do not_ attempt to understand yourself based on an invented idea that listening to music has damaged you. This is not at all warranted, and the link you think you've found to stutter is not at all something that's the result of tests conducted in a scientific and methodical manner. It needs to be, or otherwise you're highly likely to simply convince yourself on a certain take. If you've got medical or medicinal concerns, you've got to go see a doctor.