Hydrosonic diving communication amplifier system

• Main Author: ACKS; ROBERT S
• Format: Patent
• Language: English
• Published: 28.01.1975
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TELEPHONIC COMMUNICATION

Intelligible audio communications between a diver and a surface boat, or from the occupant of a recompression chamber to the outside, are ensured by interposing an electronic system between a microphone and a speaker to block major portions of gas-flow noise generated as the gas is transferred. A preamplifier stage is electrically connected to the microphone, and a preamplifier filter defines the passband of composite signals composed of gas-flow noise and audio communications. An attenuation stage receives the composite signals and further excludes signals lying outside the composite signals' passband, and notches out high intensity gas-flow noise concentrated at a particular noise frequency predetermined by spectral analysis of the composite signal. Necessarily, a portion of the audio communications, centered about the noise frequency, is also blocked; however, the remainder is sufficient to enable reconstruction of intelligible speed at an interconnected speaker.