"Blind Sight: The Next Generation of Sensory Substitution Technology" features devices that use musical tones, vibration, puffs of air and electrical stimulation of the tongue—among other methods—to assist blind people as they navigate their environment. This article appeared in Discover magazine in April 2014.
"Seeing In Tongues" from RadioLab shares the story of a woman who is blind and who uses a device which translates visual information into a pattern of electrical stimulation on her tongue.
Neuroscientist David Eagleman's 20 minute TEDTalk, "Can We Create New Senses for Humans?", presents current applications and future opportunities for sensory substitution devices.