Kgfrompa, this same thing just happened to me 2 weeks ago. I was on inhaled colistin, no other antibiotics (hadn't been on IV's for 6 months), and all of the sudden one day my ear closed, I lost hearing, & got a loud, screeching ringing in my left ear. Has been there ever since & hasn't gone away. I have seen 3 different DR.'s & no one can give me any answers. They all say it could not have been from the colistin, but I find it ironic that I found your post about this too. Looks like this happened to you in April. What is your status now? Has the ringing gone away? Have you gotten any answers? This is driving me crazy & I'm very concerned. Thanks for your help.