This post is old but I thought I’d reply as it might help someone in the future as it has helped me now.
I experienced the same - ear ringing (tinnitus) in my right ear after being on 50mg Iodoral for about a month (before that I built up from 6.25mg over 4 weeks). I was a bit baffled and checked the forum here to see if anyone else had experienced the same, whether it could be related to the Iodine or not. I decided to reduce the dose, did pulse dosing, salt loading, Vit C and I also switched to Lugols to see if that made a difference with the ear ringing but it didn’t. (I did notice though that the salt loading and pulse dosing helped with my constipation side effect!) Then I saw that someone replied that ear ringing could be connected to magnesium and B12 deficiency, I am already taking enough B12 so I cranked up my magnesium (I recently switched to ionic magnesium as apparently is best absorbed). First I took a big dose once a day but I only saw a positive effect when I divided the portion in 3 times a day (200mg per dose/600mg per day in total) and the ringing is gone! I also put a few drops of hydrogen peroxide in my ear a couple of days ago for 15 minutes while lying down, just in case there was an inflammation, so maybe that helped too?