Need more trebel for BT voice conversations

[GrononS]

Hey all,
I am having an issue with several of my Bluetooth earpieces (I've tried several because of this issue) where I have too much bass and not enough treble when talking to other people. They almost sound muffled and it is annoying to have to constantly ask them to repeat themselves.
Does anyone know of a program that will let me adjust the bass / treble of my BT headset / window mobile audio so that I can understand them better?
Thanks for any help!

Brian