A method of personalizing one or more parameters of a processing algorithm for use in a hearing aid of a specific user comprises



Performing a predictive test for estimating a hearing ability of the user when listening to signals having different characteristics;
Analyzing results of said predictive test for said user and providing a hearing ability measure for said user;
Selecting a specific processing algorithm of said hearing aid,
Selecting a cost-benefit function related to said user's hearing ability in dependence of said different characteristics for said algorithm; and
Determining, for said user, one or more personalized parameters of said processing algorithm in dependence of said hearing ability measure and said cost-benefit function.