Video Relay Service (VRS)
Video Relay Service (VRS) allows a more natural telephone communication between Sign Language users and voice telephone users. This service is easily accessible from home, office, or when you're traveling. Communication flows through a qualified video interpreter via a stand-alone videophone; or desktop or laptop computer with a webcam and appropriate free software. This service requires high-speed internet service such as DSL, cable modem, or mobile broadband card.
For more information:
List of VRS Providers

VRS with Voice Carry-Over
Video Relay Service (VRS) with Voice Carry-Over (VCO) allows a deaf or hard-of-hearing user, who prefers to voice for himself or herself, to speak directly to the other person while a video interpreter signs what the hearing person is saying. A person with some hearing would hear the other person talking.