The Ameriphone VCO, by Clarity, is designed for deaf and hard-of-hearing people who wish to use their voice to speak on the phone. Features: Built-in text answering machine Supports normal TTY communication (45.5 and 50 baud) Visual ring indicator Programmable emergency button transmits user's name, address and phone number in text for quick response by emergency services If used as an amplified telephone: Increases incoming sounds up to 26 decibels Adjustable tone control (600-2400Hz)Extra-loud (85+ decibels) ringer with adjustable ring volume Hearing Aid T-Coil compatible handset