AT&T, a provider of wireline and wireless communication services, has launched video relay service (VRS) app for iPhone 4 that enables deaf and hard of hearing users to make VRS calls.

AT&T VRS service enables a person who uses American Sign Language (ASL) to place a relay call to a hearing person by communicating through a certified ASL interpreter.

The AT&T VRS app users can launch the app, log-in, and then can either choose to place a VRS call by selecting someone from their contact list or by manually dialing a number. AT&T ASL interpreter who initiates a FaceTime video call with the user is then contacted by the app.

The ASL user will be connected to the hearing person by the interpreter, and will relay the conversation between the two parties through ASL.

AT&T customer information services senior vice president Susan Johnson said now their users can make a VRS call at Wi-Fi hotspots using iPhone 4, which makes VRS easier and more accessible for everyone.

AT&T VRS will also provide users with a ten-digit telephone number and supports all the FCC required 911 emergency capabilities.