When you are using the Phone application, use the elements especially designed for the Phone:

• Volume Buttons - The volume buttons are under the Jump button. Press + to increase and - to decrease volume, while using the phone.
• Mute Call On/Off - While on a call, press the left shoulder button to mute your side of the conversation. Press again to un-mute.
• Speakerphone On/Off - While on a call, press the right shoulder button to turn on speakerphone. Press again to turn speakerphone off.
• Headset Jack - Plug your hands-free headset into the jack just below the Cancel button. If you are using an active headset, read the instructions in Using an Active Headset.
• Keyboard Dial Pad - Use the embedded keyboard Dial Pad to easily dial with just your right hand.
• End Call and Send Call Buttons
  
  • Press to end a call or to clear the screen of a number you've typed.
  • Press to place a call to the phone number you've typed or highlighted in a list.
• Speaker - When using the phone as a handset, position the speaker (located by the Directional Pad) to your ear.
• Microphone - While on the Phone or when making a voice recording (in MMS), speak into the microphone, adjacent to the wheel.