1. While on a call, to adjust the call volume, press the Volume keys.
   
2. Tap Mute to mute the call.
   
3. While muted, the Mute icon will appear in the Notifications bar.
   
4. Tap Speaker to enable speaker phone.
   
5. While the speaker is enabled, the Speaker phone icon will appear in the Notifications bar.
   
6. Tap Add call to begin a conference call.
   
7. Tap Headset to turn on Bluetooth.
   
8. While Bluetooth is enabled, the Bluetooth icon will appear in the Notifications bar.
   
9. Tap Hold to pause the call.
   
10. Tap Unhold to resume the call.