You can purchase an optional headset to use with your BlackBerry smartphone.
If you use a headset, you can use a headset button to answer or end a call, or to turn on or turn off mute during a call. Depending on your smartphone model, you might be able to use a headset button to make a call using a voice command.
Depending on your headset, you might also be able to use a headset button to pause, resume, skip, or adjust the volume of audio or video files.
For more information about using the headset, see the documentation that came with your headset.