The IP Relay Service is a service designed to help people that are deaf or hard of hearing. It allows them to send text messages to the service and have operators, place a call to the desired party and then read the message to them.
While a very handy service, some people take advantage of it and use it for pranks phone calls. Normally, I would say this is a bad thing. However, if it weren't for these prank calls, we would never know about "Operator 7624". Unfortunately, all we know is that she is female, has a good sense of humor, and has a very hot voice!