Abstract: This invention relates to electro-acoustic transducers such as is generally indicated at 10 and which comprise a body 11 defining a chamber 12, a plate 13 bearing a micro-phone or speaker 14 to which is attached a stalk 15, a diaphragm 16, connectable to the stalk 15, which extends substantially across the chamber 12, an end piece 17 and an end cap 18. The end piece 17 has a kidney-shaped recess 21 which provides the main communication path between subsidiary inlets/outlets 19 and a main inlet/outlet 20. When the channel 22 is closed off by the end cap 18 it is effectively in the form of a tube and constitutes a Thuras tube. The length of this path effectively creates a long discharge path between the wearers' ear and any grounded metal part within the transducer and hence protects against electric shock.