How much hearing damage does it take to truly affecting your production abilities?

Nah, I've definitely subjected mine to a fair bit of abuse before wisening up, so yeah, I have only myself to blame! It really hasn't negatively affected me at all though, only in absolute silence does what little ringing there is get a bit vexing

But that is absolutely normal, even my doctor told me everyone hears a slight hiss when in total silence, there's no way around to it, I think it's the blood in the brain flowing or something
 
Mine craps out around 15k. But, I'm 33 and haven't really taken good care of my hearing at all. To be honest, it hasn't changed from the time that I was about 22 years old.