For those who are deaf or hard of hearing, cell phone use has largely been limited to messaging. But technology is catching up: Researchers from Cornell university and their colleagues have created phones that allow deaf people to communicate in sign language – the same way hearing people use phones to talk.
Since the project, Mobile ASL (American Sign Language), started four years ago, the researchers have published several academic papers on their technology. The first prototypes were created last year and are now in the hands of 25 deaf people.

A student demonstrates the Mobile ASL software on a smartphone
INSET:
A picture of the software tracking the student as she signs
Because the software requires efficient motion capture, the researchers had to also make video compression software that could deliver video at about 10 frames per second. They also had to work within the standard wireless 2G network, which only allows transmission of video at about 15-20kb per second. This is a relatively small amount of data when compared with an online video, which travels at about 600kb per second.
Researchers learned that the deaf often use only one hand to sign, depending on the situation.
And they found that when two people are talking to each other, they spend almost the entire time focused on the other person’s face.