I think this is a great question! I'd be interested in some of the responses.

I too got cisplatin and shortly after noticed some hearling loss and ringing in the ears. I had water in my right ear that muffled sounds then it cleared up. I got sick in December and the muffled sound came back. I can hear but it's best if you talk closer to my left side. I've been also been getting a ear popping sensation (like on a plane), I see the audiologist in a couple of weeks so I'll ask about the hearing aids!