The invention relates to an energy saving headset 100. The headset 100 comprises a power management unit 150 that is operable to reduce the power consumption of the headset 100 when a user 110 is not present. The power management unit 150 uses capacitive sensing to detect the presence of the user 110. Capacitive sensing is advantageous since it provides a flexible and reliable sensor that can accurately detect the presence or absence of a user 110 either by detecting user proximity or user contact. Moreover, in various embodiments, the sensitivity of a capacitive sensor may be adjusted to account for user movement or changes in environmental conditions, such as, for example, the presence of water, or sweat, on the headset 100 to further improve sensing reliability. The invention further relates to headsets using user presence signals based on capacitive sensing to control other functions of the headset or to control external devices to which the headset is connected, either wirelessly or by wires.