And on the subject of the CNS..

Here's something else to think about.
Misophonia, which has also been described as SSSS4..
Selective Soft Sound Sensitivity Disorder by some people that suffer with this disorder..

... a book called "Hearing: Anatomy, Physiology, and
Disorders of the Auditory System" (Academic Press, 2006) by Prof Aage
R Moller of the School of Behavioral and Brain Sciences at the
University of Texas at Dallas:

"4.3 Misophonia

Misophonia is a dislike of specific sounds. Unlike hyperacusis,
misophonia is specific for certain sounds. Little is known about the
anatomical location of the physiological abnormality that causes such
symptoms but it is most likely high central nervous system
structures".