Hi,
For a PPL, you only need a Class 2 medical. For this, the hearing requirements are:
(a) Hearing shall be tested at all examinations. The applicant shall be able to understand correctly ordinary conversational speech when at a distance of 2 metres from and with his back turned towards the AME.
The audiogram only comes into the equation if you wish to add an instrument rating to your PPL.
For more info, check out:
http://www.jaa.nl/jar/jar/toc00000528.htm
This site gives details of the medical requirements for JAA Class 1 and 2 Medicals.
I have tinnitus in my right ear (high freqency). I recently got a Class 1 Medical, so you shouldn't have a worry.
Hope this helps, and good luck!
Barney