Lg Electronics CU400 用户手册

TTY modes are as follows :

- Users who cannot talk and hear send and receive a

text message through TTY equipment.

- Users who can talk but cannot hear receive a text

message and send voice messages through TTY
equipment.

- Users who can hear but cannot talk send a text

message and receive voice messages through TTY
equipment.

Allows you to attach a TTY device enabling you to communicate with parties also using a TTY device. 
A phone with TTY support is able to translate typed characters to voice. Voice can also be translated into characters
and then displayed on the TTY.

TTY Full

For hearing-

text message transmission, 

operator required

/speech- impaired

text message reception

TTY+TALK

For hearing-impaired

can talk

voice transmission, 

operator required

text message reception

TTY+HEAR

For speech-impaired

audible

text message transmission, 

operator required

voice reception