Abstract: A person monitoring system, such as a baby monitor a monitored unit including a microphone for transducing radiated sound waves and sound waves emanating from the person to a received audio signal and circuitry for removing from the received audio signal a portion of the received audio signal corresponding to the radiated sound waves to provide an audio signal corresponding to the sound waves emanating from the person.

Abstract: An intake sound introducing apparatus is disclosed. An intake sound introducing apparatus may include a lining member attached to a lower surface of a bonnet hood. The lining member may generally define a communication passage. The communication passage may include an engine compartment side opening and a dash panel side opening.

Abstract: An air supply system which communicates between the compressed air supply and the mouth of a scuba diver utilizes a sealing cup which surrounds the mouth to define a breathing/microphone chamber into which the diver can speak. In addition to this chamber into which the diver can breath, a mouthpiece on an airpipe which passes through the sealing cup can be quickly forced into the mouth for direct breathing through the mouth into the air tube, bypassing the breathing chamber defined by the sealing cup in the event this chamber becomes flooded.

Abstract: A vocal sound muffling device having an elongated tubular body providing an elongated tubular cavity, a mouthpiece on one end of the body providing an inlet into the cavity for vocal sound waves and atomized fluids, a closure on the other end of the body having a fluid outlet therein for regulating fluid flow from the cavity, and cellular material in the cavity intermediate the inlet and outlet for attenuating the vocal sound waves.

Abstract: An acoustical voice tube, comprising an acoustical hollow upper piece and an acoustical hollow lower piece in hinged connection permits voice or sound tube positioning over a large area without changing the sound characteristics.

Abstract: An underwater speaker system having a pressure equalization system enabling the speaker to operate in its intended fashion over a wide range of water depths, e.g. from two feet up to sixty feet. Water pressure is applied to a diaphragm that forms one wall of a variable volume an internal face of a speaker membrane. Pressures are equalized on opposite faces of the membrane to enhance speaker performance.

Abstract: A bubble silencer for use with scuba equipment is comprised of a flat flexible enclosure attached to a scuba regulator valve. Exhaust bubbles issuing from the regulator into the enclosure coalesce into large air parcels to be expelled at low velocity through a rearward exit port. The large size and low velocity of the exhaust bubbles leaving the enclosure are much quieter than the small high velocity bubbles issuing from the regulator itself.

Abstract: An underwater voice communicator in which the preferred embodiment comprises a pair of tapered tubes in communication with a diver's mouth. The tubes are constructed of a material having a sound impedance similar to the sound impedance of water. Sound energy issuing from the mouth of a diver is reflected down the length of the tapered tubes to an area of the tube that concentrates the sound for injection into the surrounding water.

Abstract: Direct voice communication with simultaneous two-way transmission is possible with a communicator having the earpiece of the communicator at one station connected by flexible plastic tubing to the mouthpiece of a communicator at another station, the two stations being connected by two independent voice channel tubes. The provision of cross-connected channels between the mouthpiece and the earpiece of two communicating stations permits normal conversation with simultaneous two-way transmission to occur in the manner of telephonic transmission rather than requiring sequentially alternating transmission between stations as necessary in using single voice tube communicators where destructive interference occurs between sound waves transmitted simultaneously in opposite directions in a voice tube.

Abstract: A crash helmet for use by motorcycle drivers or riders has a rigid shell; a first flexible acoustic tube a first section of which extends into and has a bell horn in the region of the mouth-protecting part of the shell, and a second section extending from the shell through the opening in the neck-surrounding part of the shell; a second flexible acoustic tube a first section of which extends into and has a sound-intensifying terminal portion in the region of an ear-protecting part of the shell, and a second section extending outwardly through the aforementioned opening of the shell; first and second additional flexible acoustic tubes respectively corresponding to the second and first tubes and having first sections installed in the shell of a second crash helmet; and a quick-release coupling respectively connecting the second sections of the first and second tubes with the second sections of the second and first additional tubes.

Abstract: A communications device for use under water by a human speaker. A tubular base member has a mouthpiece located at one open end thereof and an inflatable air bag mounted about another open end thereof. In use, the speaker places the mouthpiece around his mouth to form an air seal therebetween and blows into the air bag to partially inflate it. When so inflated, the speaker talks into the device with voiced sounds being transmitted to the surrounding water through suitable transmitting means attached to the base member, preferably the air bag itself. During talking, the air bag receives and returns the air used by the speaker, thereby effectively preventing the escape of air bubbles from the device which otherwise interfere with communications. The air bag is preferably an elongated, flexible balloon which can be stretched into an extended position when speaking into it under water.

Abstract: A sponge sound absorbing article for placement on the side frames of eyeglasses for workers employed in very noisy environments. The sound absorbing article eliminates any sound gap between the sides of the eyeglass frames and conventional earmuffs to protect the ears from sustained exposure to dangerous noise levels.