Are there any devices that help people with hearing impairments to use the phone more efficiently?

TTY, a telecommunication device with keyboard and visual display for people who are deaf, hard of hearing and speech disabled allows the user to use the phone more efficiently. In California, the California Relay Service (CRS) enables a person using a TTY to communicate with a person who does not use a TTY. An operator transcribes the conversation into words, which are displayed, on the screen of the TTY to the person with hearing impairment.For more information, call MCI CRS at 1-800-735-2929 TTY 1-800-735-2922 Voice Sprint CRS at 1-800-877-5378 TTY 1-800-877-5379 Voice.There is also the Sonic Alert Telephone Signaler, which attaches to a lamp and flashes the light when the phone rings. For more information, call Dynamic Living at 1-800-940-0605 or visit their web site at http://www.dynamic-living.com.