Hi wow, thanks for that. Here are my answers:

Onset: It was quite sudden. I had a bad inner ear infection in January 05,for which I was put on antibiotics. The pain etc went, but I was left with the constant noise afterwards.I dont remember having it before the infection.
Pitch: A high pitch whistling sound, bit like a kettle whistling. It never changes pitch either.Sometimes there will be an additional high pitch noise that comes and goes, but the whistling is contstant.
Duration: The noise is absolutely constant, never been away since Jan 05
Pressure: Seems to alleviate it a bit when I press my ears. THe noise doesnt go away, but generally my ear feels blocked most of the time, which did seem easier when pressing with my hands.
I have had my ears syringed which did nothing either.
I also feel constantly thirsty, even when I drink around 3 litres of water a day I still feel thirsty next morning, and at the moment am really struggling to get up in a morning to go to work.
Im generally healthy, train 3 times a week in kung fu and do other stuff like cycling.
Really appreciate your offer of help,
Thanks
Louise