Abstract: A piezoelectric electro-acoustic device for converting an electric signal into an acoustic vibration and/or for converting acoustic vibrations into an electric signal is disclosed. The device employs at least two opposing concave membranes having a single axis of elongation tangent to the curvature thereof. The membranes face each other and are connected to electrodes. Upon changes in electric current provided to the membranes, the membranes will vibrate towards one another to thereby displace air located between the surfaces thereof. This dipole horn structure provides a high conversion efficiency as well as a true 360.degree. acoustic response.