Sprint Nextel 755P ユーザーズマニュアル

A TTY (also known as a TDD or Text Telephone) is a telecommunications device that allows 
people who are deaf or hard of hearing, or who have speech or language disabilities, to 
communicate by telephone.

Your device is compatible with select TTY devices. You can connect a TTY/TDD machine, 
headset, or hands-free kit to your device through the headset jack while this mode is 
enabled. Please check with the manufacturer of your TTY device for connectivity 
information and to ensure that the TTY device supports digital wireless transmission.

When establishing your Sprint service, please call Sprint Customer Service via the state 
Telecommunications Relay Service (TRS) by first pressing 711 and then pressing Talk

. 

Then provide the state TRS with this number: 866-727-4889.

Sprint recommends that TTY users make emergency calls by other 
means, including Telecommunications Relay Services (TRS), analog 
cellular, and landline communications. Wireless TTY calls to 911 may 
be corrupted when received by public safety answering points (PSAPs), 
rendering some communications unintelligible. The problem 
encountered appears to be related to TTY equipment or software used 
by PSAPs. This matter has been brought to the attention of the FCC, 
and the wireless industry and PSAP community are currently working 
to resolve this.