Abstract: A diving helmet apparatus includes a diving helmet that is based on a 98th percentile anthropomorphic head form. The helmet is relatively smaller and lighter than convention diving helmets. The center-of-gravity and center-of-buoyancy of the helmet are co-located to reduce diver fatigue. The apparatus has unique neck dam latch devices that use cam mechanisms. The neck dam and the opening in the helmet that receives the diver's head both have a substantially oval shape that contributes to a significant reduction in the volume of the helmet. The apparatus also uses unique face mask latch devices. The neck dam and face mask latch devices allow a diver to easily secure and remove the helmet and face mask without the assistance of dive tenders.

Abstract: A tunable contact microphone is fabricated from nanometer size piezoelectric materials. The piezoelectric nanostructures are deposited on a flexible substrate or tunable resonant backplane. The backplane can be designed to vibrate at fundamental harmonic or sub-harmonic frequencies from 10 Hz to 20 KHz, corresponding to vibration frequencies of the human cranium. The backplane can be attached to a band or other material that will facilitate the attachment to the forehead, behind the ear or throat, with a preferred location being the forehead. When a person speaks, the backplane vibrates causing the nanostructures to generate electricity. The electrical signals are sent to an impedance matching preamplifier. The signal can then be sent to a communications system or fed into the microphone input of a communication system.