Hi, I developed this at the start of the year for some reason and wondered if there was a connection with the accordion and the conclusion is no really.
I too at times found it sensitive to my ear as the sound bellows into an ear - generally my left - except when my loud playing friend was playing very close to my right ear.
I think my ears are now de sensitised a bit and its not uncomfortable but still have the tinnitus - noticeable when quiet.
I think its louder in one ear too for me.
I have spoken to my gp and a hospital hearing test specialist (who said my hearing was fine) with regards to the accordion and there reaction was such that its not really loud to cause hearing problems (i would say a pneumatic road drill or rock concert is loud now) - unless you play in a small kitchen cupboard
i find it therapeutic playing actually as, as this condition is noticeable when quiet its better when there is no quiet - ie have some background noise there like tv,radio,accordion etc
the general consensus is also , frustratingly , that there is no remedy and its one of those 'live with it' problems
dont want to worry you but it can indicate an underlying serious problem - especially if one ear only - so worth checking out with a gp