Is there any research into other ways to 'get sound into the brain', generally speaking? If so: some pointers would be much appreciated.

After being hard-hearing since early childhood (bad living conditions -> tuberculosis -> ototoxic antibiotic, streptomycine iirc), my mum had a CI for a # of years. But due to infections, it got removed at some point. Since then I've always wondered if there's other routes to get sound into the brain. Say, using vibrations on the skin. Or an electrode-stuffed 'helmet' of sorts.

Even if temporary, it can be a life-changing experience for someone who's never experienced sound.

Any research in that direction?