Dear Ellie,
you should ask Michael Stone, formerly a coworker of Brian Moore in Cambridge, now in Manchester
michael.stone@xxxxxxxxxxxxxxxx. He wrote a very elaborate hearing loss simulator in Matlab with non-linear effects to mimic changes in compression and filter bandwidth etc, based on their psychoacoustic work. He may be prepared to share it with you if you ask nicely.
I also have the suspicion, but do not know for certain, that some of Ray Meddis' code can also be used to mimic hearing loss. And there may be others.
Best,
Jan