Israeli startup MeQ Inc has developed earphones that adapt to your unique hearing condition.  The Even Headphones incorporate an “earprint” facility which allow the listener to lower the volume and protect against further hearing problems from being over-exposed to loud music.

http://www.jpost.com/Business-and-Innovation/Tech/Israeli-start-ups-headphones-adapt-to-peoples-unique-earprints-459192

https://www.engadget.com/2016/06/28/even-headphones/