Active Noise Reduction (ANR) improves sound quality by reducing unwanted noises. Its circuitry reads the incoming sound waves, electronically inverts them in phase, and plays the resulting inverted sound waves through precisely engineered speakers. 

 

ANR reduces low-frequency sound below 600 Hz, such as those created by helicopter rotors. ANR is ineffective against high-frequency sound which is easily attenuated by installing the ANR speakers in large-volume earcups.

 

Your helmet must have earcups that seal against the head. A good seal can be obtained by using silicone-gel earseals, which are included with the ANR kit, and by adjusting the helmet’s retention and earcup pressure.

 

ANR can be powered by either a 9-volt battery or by aircraft power. A high-quality 9-volt battery should last for 12-15 hours. The active noise reduction modules require a stable power supply, so we recommend Dura-Cell and Energizer batteries or a regulated aircraft power source.

 

ANR kits include a pair of ANR modules, a 9-volt auto-shutoff battery pack, silicone-gel ear seals, insulation, speaker covers, and double-sided tape. Earcups, aircraft power supply, and helmet cords are not included.

 

The ANR system reduces unwanted sound in the range of 50 to 600 Hz, with peak reduction of up to 18db at approximately 200Hz.

 

 

Environmental Protection Agency noise reduction ratings (NRR) do not apply to ANR systems, only to passive noise reduction products such as headsets, earcups, or earplugs.

 

Helmets with ANR should be used with the ANR turned on. When the ANR is turned off, the passive sound attenuation of the earcup will be less than if ANR had not been installed.

 

You can purchase one of our specialized helmet cords that incorporate both communications and the power lead for ANR.