I can't understand the criticism about the inherent odour. The only point of criticism from other reviews that I can confirm is the very bright flashing light when switched on. Of course, this is not visible to the person wearing the mask as the light is on the outside. It can only be annoying for bed neighbours. But not a problem for us, as we both have the mask and can therefore both listen to our own music. Battery lasts about 3 nights. I think it's a shame that it doesn't switch off automatically after 3 hours, for example, as it's designed for sleeping. So it really drains the battery power if you always have it on all night.