For hard of hearing people, speech sounds are recognizedelectronically and displayed on eyeglasses at syllable speed,consonants are shown as a symbol resembling a hand sign, and vowelsby the symbol's location in a quadrant display, or by color.
Method and apparatus for automatic cuing
Cornett, RO., & Beadles, R. (1990). IPC No. U.S. Method and apparatus for automatic cuing. (U.S. Patent No. 4972486).