I suffer from tinnitus and hyperacusis so I was looking for a white noise generator to mask it. Most of the reviews of the Marpac were great, but I did read several that mentioned an unpleasant high pitched sound that was produced alongside the white noise. When I received the item and turned it on, I heard this high pitched noise immediately. I left the unit on for a bit to see if I would stop hearing it, but it continued to bother my ears. My partner, who has normal hearing, also found it annoying. I sent it back. I've continued to use my fan and air filter to produce masking sounds instead.Amazon provided quick and awesome service as per usual.