Abstract: A wireless communication system, for example for underwater divers, wherein the receiver portion and the transmitter portion of the system are mounted at the user's ear and mouth, respectively, by a single strap. The single strap is also used to maintain the communication system electronics and the mouth mask securely in place.

Abstract: A microphone for use in underwater applications. The microphone includes a dynamic magnet and coil assembly in a housing which incorporates a hydrophobic membrane. The membrane is sufficiently porous to permit air to pass therethrough. However, water cannot pass through the membrane. The housing permits water to drain away whereby a superior underwater microphone is obtained. This invention provides the diver with a military-style noise canceling microphone that retains exceptional sound reproduction quality because it is not encapsulated. However, the new microphone can be repeatedly exposed to the marine environment without failure.

Abstract: A wireless communication system, for example for underwater divers, wherein the receiver portion and the transmitter portion of the system are mounted at the user's ear and mouth, respectively, by a single strap. The single strap is also used to maintain the communication system electronics and the mouth mask securely in place.

Abstract: A wireless communication system, for example for underwater divers, wherein the receiver portion and the transmitter portion of the system are mounted at the user's ear and mouth, respectively, by a single strap. The single strap is also used to maintain the communication system electronics and the mouth mask securely in place.

Abstract: A control system which enables a diver to electronically switch between voice operated (VOX) operation and push-to-talk (PTT) operation by actuation of the existing momentary contact PTT switch used in most diver communication systems. A counter and multivibrator arrangement is employed to alternate between PTT and VOX modes in response to a pair of quick depressions of the PTT switch within a pre-determined time. An audio tone having a duration which identifies which mode of operation has been enabled is also generated and is available for input to the diver's earphone amplifier. The control system includes a frequency selective VOX enabling circuit which takes advantage of the repetition of vowel pitch pulses found in human speech. The circuit continually locks onto these pulses when they last for a few cycles but ignores noise (as found in diving masks) which has only random spikes without the periodic repetition of vowel frequencies in speech.