A headset that can detect the voice activity of a user includes an inner microphone generating an inner microphone signal; an outer microphone generating an outer microphone signal, wherein the inner microphone and outer microphone are positioned such that, when the headset is worn by a user, the inner microphone is disposed nearer to the user's head; and a voice-activity detector determining a sign of a phase difference between the inner microphone signal and the outer microphone signal and generating a voice activity detection signal representing a user's voice activity when the sign of the phase difference indicates that the outer microphone received an audio signal after the inner microphone received the audio signal.