BenQ P51 - Manual (Page 60)

48 Phone operation
Loudspeaker
Turn the loudspeaker on and continue your conversation while using other phone functions.
This is a great feature for allowing your colleagues to participate in your call.
1. First make a phone call.
2. Tap , Menu > Turn Speakerphone On , or long press Send to turn on the
speakerphone function.
3. To turn off the loudspeaker, tap , Menu > Turn Speakerphone Off , or long press
Send .