Abstract: A waterproof device for communicating by radio to a swimmer or other user includes a radio frequency receiver supplying a signal to a pressure transducer, a hollow, flexible sound conducting tube connected to an output of the transducer, an ear hook for attachment to an ear of a user of the apparatus, the ear hook being shaped to retain and conduct the tube from the receiver to the ear; and an ear piece shaped to fit in the ear of the user and having an opening therein for conducting sound provided via the tube to the ear.