When TTY/TDD is turned on, the 
icon appears in the title bar.
1Connect a TTY/TDD device to your smartphone using the headset jack.
2Open Phone 
.
3Open the application menu and tap Preferences & Accounts.
4In TTY/TDD, tap On or Off.
Turn HAC on/off
To use your smartphone with a hearing aid, turn on the HAC feature. This feature ensures that your phone can make the necessary connection with a hearing aid.
When HAC is turned on, the 
icon appears in the title bar.
1Open Phone 
.
2Open the application menu and tap Preferences & Accounts.
3In HAC, tap On or Off.
Use SIM Toolkit
The SIM Toolkit app gives you access to services from your wireless service provider such as account information, payment and news. Features vary by wireless service provider.
NOTE Not all wireless service providers support the SIM Toolkit app. If SIM Toolkit does not appear in the Launcher, your wireless service provider does not support the app.
1Open SIM Toolkit 
.
2View and work with the features displayed.
76 Chapter 6 : Phone