1) Answer/End a call: Double Tap on either earbud.

2) Reject an incoming call: Tap & Hold either earbud for 3 seconds.

3) Call Mute is not set by default. It can be assigned to Single, Double or Triple Tap under the Phone Call options in Touch Gestures.

4) Call controls are customised separately from music controls in the Noise Audio App (options: Answer/End Call, Reject Call, Call Mute, None).

5) The same prompt tone plays when a call is rejected or ended.