first ide try to eliminate the system by asking someone else without a hearing problem to listen .the effect you describe is quite dramatic and noticeable. even though to me it makes sense that the small mic\speaker in the hearing aid are overloaded.
in my system (nuforce icon hd arcam delta 120 b&w dm 580)i used to enjoy 70's ecm albums (early metheny jan garbarek ralph towner)but could't enjoy led zeppelin everything collapsed like you describe so this helped with clarity
swap all the tubes to nos ge jan tubes
get a loki or some transpenant mild eq
get the ifi itube (it has a ge tube it's adding to the preamp) use it with zero gain as a buffer before or after the preamp
get really nice open headphones and amp i'm happy with hd700 and the icon hd but according to your system you have a finer taste than me so try and see what you like maybe staxx
in my system (nuforce icon hd arcam delta 120 b&w dm 580)i used to enjoy 70's ecm albums (early metheny jan garbarek ralph towner)but could't enjoy led zeppelin everything collapsed like you describe so this helped with clarity
swap all the tubes to nos ge jan tubes
get a loki or some transpenant mild eq
get the ifi itube (it has a ge tube it's adding to the preamp) use it with zero gain as a buffer before or after the preamp
get really nice open headphones and amp i'm happy with hd700 and the icon hd but according to your system you have a finer taste than me so try and see what you like maybe staxx