Abstract: An earpiece includes an electro-acoustic transducer and a housing. The housing supports the electro-acoustic transducer such that the housing and the electro-acoustic transducer together define a first acoustic volume and a second acoustic volume. The electro-acoustic transducer is arranged such that a first radiating surface of the transducer radiates acoustic energy into the front acoustic volume and such that a second radiating surface of the transducer radiates acoustic energy into the second acoustic volume. A front port couples the first acoustic volume to a space outside the housing, and a rear port couples the second acoustic volume to the space outside the housing. Respective outlet ends of the front port and the rear port combine before exiting the housing via a combined exit volume and an exit port.