HTC One M9 - Manual (Page 278)

Settings 265
3. Select the Hearing aids option.
4. Select Sidetone to get voice feedback in a hearing aid.
CDMA Call Settings
Use these options to enable hearing aid compatibility, and adjust several call settings, such as
teletypewriter and DDTM.
1. Tap > > Settings.
2. Tap Call.
3. Tap CDMA call settings.
TTY Mode
A TTY (teletypewriter, also known as a TDD or Text Telephone) is a telecommunications phone that
allows people who are deaf, hard of hearing, or who have speech or language disabilities, to
communicate by telephone.
Your phone is compatible with select TTY phones. Please check with the manufacturer of your TTY
phone to ensure that it supports digital wireless transmission. Your phone and TTY phone will
connect using a special cable that plugs into your phone’s headset jack. If this cable was not
provided with your TTY phone, contact your TTY phone manufacturer to purchase the connector
cable.
When establishing your Sprint service, please call Sprint Customer Service using the state
Telecommunications Relay Service (TRS) by first dialing . Then provide
the state TRS with this number: 866-727-4889.
To turn TTY Mode on or off:
1. Tap > > Settings.
2. Tap Call.
3. Tap CDMA call settings > TTY mode.
4. Tap TTY Full, TTY HCO, or TTY VCO. Tap TTY Off to turn TTY mode off.
Note: When enabled, TTY mode may impair the audio quality of non-TTY phones connected to the
headset jack.
Warning: 9-1-1 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 9-1-1 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 the PSAP community are currently working to resolve this.