DJ...
A co worker received a big package the other day from FedEx. MacBook Pro that he intends on using for his moonlighting gig of Disk Jockey. With the exception of 2 turntables all his gear is electronic. Years ago, he carried boxes of LP records and now everything is on a hard drive.If there's an obscure song request not in his collection, he can quickly download it from a library he subscribes to.
He hires out for parties, Bar Mitzvahs and a few weekends a month he plays a night club until 3am.
I asked about the volume of the music played and he agreed when the speakers are behind him the roar would send him home with his 'hissing' from the sounds but lately he's been moving the speakers away from the DJ booth and has sound insulating headphones to lower the volume.
Ask any professional musician about ringing in the ears (Tinnitus) and actually any loud volume sound will do this. Actually, you don't have to be a musician to experience hearing loss. Lots of factory workers who are around machinery for hours on end without some form of hearing protection will also experience the same effect.
Back to the DJ job. My coworker says the money earned from his night job goes directly into a fund for family trips and vacations. I thought that was a great idea!