An ultra-compact headset device including both speaker and microphone capability in at least one earphone overcomes the minimum size requirements of previous headsets by controlling the speaker and microphone functionality so that each earphone functions either as a speaker or microphone, but never both at the same time. Various embodiment headsets may include a pair of earphones each with one or more transducers capable of converting electrical signals into sound and vice versa. The ultra-compact headset may be wirelessly coupled to a mobile device, such as a cellular telephone or smart phone.