A headphone system is provided that includes a first earpiece, a first front microphone coupled to the first earpiece to receive a first acoustic signal, a first rear microphone coupled to the first earpiece to receive a second acoustic signal, the second acoustic signal being toward the rear of a user's head relative to the first acoustic signal, and a detection circuit coupled to the first front and rear microphones and configured to compare a front signal derived from the first front microphone to a rear signal derived from the first rear microphone and to selectively indicate that the user is speaking based at least in part upon the comparison.