Came across the web page of Frank A. Russo, and found a very interesting paper on Hearing Aids and Music discussing the auditory design of hearing aids:
Whether the hearing aid wearer is a musician or merely someone who likes to listen to music, the electronic and electro-acoustic parameters described can be optimized for music as well as for speech. That is, a hearing aid optimally set for music can be optimally set for speech, even though the converse is not necessarily true.