I"m confused as I've been working as a flight attendant for the best part of 12 years
And that unfortunately is the problem. It saddens me when I see how many of my colleagues have suffered with hearing loss from working as a flight attendant. After 6 years of short-haul flying, I too have started to suffer with tinnitus and have some hearing loss in the high frequency range.
What's interesting is that our company manual states that in order to achieve maximum hearing protection, flight crew must wear headsets covering both ears and that the interphone should be used appropriately to ensure clarity of conversation between crew members. It's a shame that they don't afford the same kind of protection to cabin crew.
I don't necessarily think that the volume of the noise is the issue (certainly not the aircraft type that I operate), but it's more to do with prolonged high pitch sound that emanates from the slipstream around the aircraft. After a long 10-12 hour day, when I lay in bed in silence, the ringing is stark!