Hi,

i am looking for some sort of (academic?) document which has some sort of info, statement about the natural loss of high frequencies for people between the age of 20 and 40 years old. As far as I always thought was true is that starting from a young age you gradually have some loss of frequencies, or shift of hearing threshold. However, now I desperately trying the find some sort of info on that topic for my ba (hon) all I can find is loss of hearing due to old age and abnormal causes.

Could someone give me some advice on were I can find something like this?

Thanks in advance, maarten koster