Abstract: Disclosed is equipment for wireless transmitting and receiving audio signals in a confined area which comprises a transmitter receiver and battery pack. The receiver including a bracket with which the receiver may be detachably secured to a surface such as a table or chair arm and whereby access to the fasteners with which the bracket means is secured to the surface is restricted. The receiver and battery pack have complementary dovetail means by which the battery pack and the receiver may be operatively secured together in electrical communication, the battery pack being detachable by the use of the receiver. Preferably, the bracket and receiver have a latchable dovetail connection means whereby the receiver can be hooked to the bracket and removed only by authorized people using an appropriate key.