When I was researching noise cancellation headphones I remember coming across many 

reddit

discussions about just this. People with hearing troubles who decided to get the cheaper and better Bose headphones that also have audio enhancing.

Anything that has a potential marketplace also has discussions. This is why 

Amy Hoy

's class has a segment just called 

painstorming

. I never took the class but 

dealingwith

did and he showed me his painstorming notes. It basically involves going to online communities -- like Reddit -- and curating discussions of pains in a specific domain.