Context: One of the first demonstrations of the ability for telecommunications to help sign language users communicate with each other occurred when AT&T's videophone (trademarked as the "Picturephone") was introduced to the public at the 1964 New York World's Fair –two deaf users were able to communicate freely with each other between the fair and another city. Various universities and other organizations, including British Telecom's Martlesham facility, have also conducted extensive research on signing via videotelephony. The use of sign language via videotelephony was hampered for many years due to the difficulty of its use over slow analogue copper phone lines, coupled with the high cost of better quality ISDN (data) phone lines. Those factors largely disappeared with the introduction of more efficient video codecs and the advent of lower cost high-speed ISDN data and IP (Internet) services in the 1990s.

Question: What company introduced the first device to help deaf people communicate through telecommunications?
Answer: AT&T

Question: What was the name of AT&T's videophone device?
Answer: Picturephone

Question: In what year was AT&T's "Picturephone" device introduced?
Answer: 1964

Question: Where was AT&T's "Picturephone" device unveiled?
Answer: 1964 New York World's Fair

Question: In what decade were more efficient ways of using sign language via video-telephony developed?
Answer: 1990s

Question: Where was the Picturephone introduced in the 1990's?
Answer: Unanswerable

Question: Where were universities able to communicate with each other at the fair?
Answer: Unanswerable

Question: What organization conducted research on ISDN phone lines?
Answer: Unanswerable

Question: How were video codecs hampered for years?
Answer: Unanswerable

Question: What was introduced to make extensive research easier over video telephony?
Answer: Unanswerable