U.S. Supreme Court Chief Justice John Roberts departs after U.S. President Barack Obama's State of the Union address to a joint session of Congress in Washington, January 12, 2016. REUTERS/Joshua Roberts

WASHINGTON (Reuters) - In an historic first, U.S. Chief Justice John Roberts used sign language from the Supreme Court bench on Tuesday as he welcomed a dozen deaf and hard-of-hearing lawyers who took part in a ceremony authorizing them to argue cases before the court.

The 12 members of Deaf and Hard of Hearing Bar Association were sworn in as members of the Supreme Court bar. After they were presented to the court for admission, Roberts signed in American Sign Language: “Your motion is granted.”Membership in the Supreme Court bar allows a lawyer to argue cases before the justices but most of its members never actually do so.

Roberts, appointed by Republican President George W. Bush in 2005, is believed to be the first U.S. chief justice to use sign language from the bench. It was also the first time members of the Deaf and Hard of Hearing Bar Association took part in a swearing-in ceremony at the court.

The lawyers then stayed for oral arguments in two cases in the ornate courtroom, assisted by an interpreter standing in front of the mahogany bench where the eight justices sit.

The lawyers were permitted to use an instant transcription service that was transmitted to electronic devices. Normally, no electronic devices are allowed in the courtroom.

One of the attorneys, Teresa Curtin of the Weitz & Luxenberg law firm, said in a statement the event was aimed at encouraging more people with disabilities to embark on legal careers. When she began her law career in the late 1980s, there was only a handful of deaf lawyers in the United States, while now there are around 250, Curtin said.

In 1982, a deaf lawyer, Michael Chatoff, argued a case before the Supreme Court, assisted by a real-time transcription system. That case concerned whether a school board was required to provide a deaf student with a sign-language interpreter. Chatoff lost the case in a 6-3 ruling.