Hearing Protection

Whilst both passive and active noise reduction techniques are available, we are at the fore-front of adaptive intelligent hearing protection and active noise reduction (ANR) which offers increased benefit in low frequency attenuation.

Active Noise Reduction (ANR)
The noise is reduced by the destructive interference of the original noise signature with a corresponding inverted signal. ANR augments the noise reduction gained from hearing protectors. Our ANR system is now available as a commercial-off-the-shelf (COTS) systems, produced under licence by HISL. Applicable to ground and deck crew, flight and other helmets, headsets or ear-insert devices, the system is currently in service on the Harrier and Sea King Mk7 fleets.

HumBUG is as an adaptive hearing protection system that selectively reduces harmful or loud noises, but lets the wearer hear other sounds normally and enables them to retain both situational and spatial awareness. It is an ear plug based hearing protection system designed so users can hear more normally in quiet noise environments without the need to remove the ear plugs.

Most traditional hearing protection devices are designed to block out sound as much as possible and simply reduce all sounds equally, so useful signals such as voices may not be heard. The user would then need to remove these traditional protectors to hear normally and replace them to provide the protection.

With HumBUG this is not necessary; the wearer can simply ‘fit and forget’. More than just a matter of convenience, this means the wearer is protected from any unexpected harmful noises and retains the ability to determine the direction from which a sound came.

HumBUG also includes an external audio input for connection to communications systems, 3D audio systems or intercoms. Versions of HumBUG, currently being developed, will adapt the volume of this external input in response to the outside noise. This means the wearer can hear the audio input when in noisy environment such as aircraft cockpits but when they move to somewhere quieter, the volume will reduce to a comfortable level.

Benefits

• selectively reduces harmful or loud noises, but lets the wearer hear other sounds normally
• the wearer can simply ‘fit and forget’
• external audio input for connection to communications systems, 3D audio systems or intercoms