This one can be used to set a baseline of your hearing, and if you're geeky enough, retest yourself the day after attending a loud concert, working with power tools, or riding a snowmobile. A few hours or even a day later your hearing acuity will be significantly reduced. It's kinda like a preview of what's to come, if you don't stop abusing your ears.

That short-term deafness is sometimes referred to as Temporary Threshold Shift (TTS). But repeated episodes of temporary hearing loss, with insufficient recovery times between exposures will eventually lead to permanent hearing loss.