Active noise-cancelling headphones
The NoiseMaster range of hearing protectors are intended for people working in VERY NOISY environments. They incorporate ANR technology, the operational use of which began in the French army more than twenty years ago with the equipment of tank and helicopter pilots. ANR has rapidly developed in armies around the world, civil services, aeronautics and the industrial world to improve the performance of traditional hearing PPE. To date, this technology is widely used in the world both in the field of personal protection and for HIFI headphones.
ANR technology is based on miniaturized electronics (2) which is placed inside the shell of the helmet. This electronics is connected on the one hand to a small microphone (1) which picks up the ambient noise and on the other hand to a small loudspeaker (3) which generates the counter-noise near the ear so as to considerably attenuate the noise reaching the eardrum.
The ANR is mainly effective in the low frequencies and therefore settles in plastic shells which deal with the medium and high frequencies. The figure (opposite) highlights the additional attenuation provided by ANR compared to passive The attenuation of hearing protection with ANR is between 30 and 45 dBA depending on the ambient noise.
- Exceptional attenuation of loud noises in the low frequencies
- Homogeneous attenuation of low-pitched noises to high-pitched noises
- Decrease in the risk of deafness related to low-pitched noises
- Improved alertness at work
- Reduced fatigue caused by loud noises
- Improved perception of the sound environment
- High quality of communication intelligibility (> 96%)
- Elimination of the feeling of acoustic confinement due to wearing a helmet
The ANR is different from other so-called “active” electronic processes on the market which are actually “passive activated” systems also called “controlled attenuation”. The latter equipment is equipped with an open flap fixed to the shell of the helmet. As soon as the noise reaches 85 decibels, the valve closes and the helmet becomes passive hearing protection. The closure of the flap is “actively” triggered by electronics which react to noise, but the hearing protection remains purely passive since there is no protection other than that provided by the shell. Only ANR has an “active” noise reduction effect.
- Machinery drivers (construction, transport, agriculture, military, etc.).
- Maintenance personnel (airports, construction sites, etc.).
- Pilots (planes, helicopters, ULM, etc…).
- Sporting activities (shooting range, rally, motorcycle, etc.).
- Any other communicating application in a noisy environment (walkie-talkie, radio, intercom, etc.).
Depending on your needs, we offer technical assistance services for the development of ANR headsets and/or the supply of modules and sub-assemblies intended for integration into specific communication systems. For military applications, TechnoFirst has notably worked with the companies ELNO and SILEC/SAGEM (France), Racal Acoustics (United Kingdom) and Gemelli (Italy).
A full range of headsets and options have been developed based on user needs and requirements with the aim of making NoiseMasters optimally effective. The range of helmets is divided into three families: protective helmet, protective helmet with audio option and communicating helmet.
Protective helmet and sound reception
Protective and communication helmet
- Autonomy: 25 hours
- Charging time: 2 hours
- Operating temperature: -15°C to +55°C
- Storage temperature: -20°C to +55°C
- Power supply: 4.8 V DC
- Attenuation in low frequencies: 15 dB in passive mode and 40 dB in active mode
- Operation in ambient up to 120 dB