It all began in 1987 with a doctoral thesis prepared and defended at the Laboratoire de mécanique et d'acoustique (Aix-Marseille Université/Centrale Marseille/CNRS), the oldest CNRS laboratory in Provence, by Christian Carme under the direction of Bernard Nayroles, on active sound absorption in cavities.
On the strength of this experience and results, Christian Carme created TechnoFirst in 1990, a company that has since become the world leader in active noise and vibration reduction technologies.
The principle of active control consists of generating a "counter-noise" that cancels out the primary noise.
That's how the first noise reduction system was born: the active noise-cancelling headphones.
There are two types of earmuffs: passive (without electronics) and active (with electronics).
In a very noisy environment, passive headphones can attenuate high frequencies (high frequencies) by 50 to 60 decibels, but low frequencies (low frequencies) by only 15 decibels. In active mode, the attenuation of low frequencies can be tripled.
Today, this technology is found all over the world, from construction site headphones to home music headphones.