A helmet based crew communication system is designed incorporating an optically driven earplug as well as active noise reduction signal processing at the crew station. The optically driven earplug is added to the helmet communication system to both increase the passive noise rejection through use of an earplug as well as well as to improve intelligibility through use of an active earplug speaker. The earplug is optically driven through free space to eliminate the wire connection of conventional active earplugs to ease helmet don and doff limitations. The earplug small size and freedom from helmet connections also allows the helmet to continue to have conventional ear cup speakers for redundancy and use in active noise cancellation. Sensing microphones of either a conventional or fiber optic type are also included for use with digital signal processing using compact low power DSP chips.
Benefit: Active earplugs for improved communication in noisy environments including industrial, medical and law enforcement environments.
Keywords: Fiber Optic, Fiber Optic, Noise, digital signal processing, earplug
