Amy Hoy
When I was researching noise cancellation headphones I remember coming across many 
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 
. I never took the class but 
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.
Abraham Kim