Blowmonkey
Bluelight Crew
I read about hyperacusis, it sounds awful, I don't think this is what people are experiencing. It sounds more like tinnitus, in fact davem used that word, and I don't think that's the same as hyperacusis.
I know tinnitus and hyperacusis are not the same thing. Hyperacusis is simply a hypersensitivity to (certain) sounds which is a common phenomena on dissociatives. Tinnitus is something else entirely. Tinnitus is also dampened with NMDA antagonists due to inhibition of glutamate, so I don't know how an NMDA antagonist like methoxetamine would cause it.
edit: NMDA antagonists have no effect on pulsatile tinnitus, which is commonly caused by vascular anomalies, so a raise in pulse or blood pressure could worsen it, same with hyperacusis.