Samsung SCH-I830MSASPR - Manual (Page 72)

64 Section 2C: Controlling Your Roaming Experience
When establishing your Sprint PCS Service, please call Sprint
Customer Service via the state Telecommunications Relay
Service (TRS) by first dialing 7-1-1 and tap Talk. Then provide
the state TRS with this number: 866-727-4889.
1. Tap the Start menu bar, and then select Settings > Phone.
2. Tap the Option tab, then select On or Off from the TTY
option and tap .
Note: In TTY Mode, your phone will display the TTY access icon
when a headset or TTY device is plugged in.
If TTY mode is enabled, the audio quality of non-TTY
devices connected to the headset jack may be impaired.
WARNING 911 Emergency Calling
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
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.