Hello Simon,
Firstly there is always a danger that your award could be removed or reduced if you report a change of circumstances. When you had your tribunal had you already reported difficulties with your hearing in your original claim. or are you reporting the change as a new condition?. Be mindful of the fact that its not the condition that you may receive an award for, its how it affects your ability to function day to day.
Nothing on this board constitutes legal advice - always consult a professional about specific problems