Pietro
It pays to be careful and wear hearing protection but there is no beating time. I understand about IEMs but does that apply to headphones too?
There's a sticky in the Headphone full sized forum, that shows various decibel reading and the exposure time to them that can cause hearing damage. Looks like it does include headphones too, not just IEMs. https://www.head-fi.org/f/threads/h...h-thread-a-diary-of-a-ear-health-noob.723464/No, for various reasons it doesn't.