Innovative acoustic devices for active noise reduction in vehicle cabins


recalm is based on the principle of Active Noise Cancelling (ANC). At the touch of a button it reduces annoying and harmful noises
for humans through targeted anti-sound.


In the company’s young history, 2019 was the year of awards. We were awarded the German Occupational Safety Award at A + A in Düsseldorf. We are also the proud winner of the Systems and Components Trophy, which was awarded to us at Agritechnica in Hanover.


Active Noise Cancelling without headphones

Noise causes stress and makes people sick. By far the most (40%) of all recognised occupational hazards in Germany account for noisy hearing [1]. Healing is not possible and hearing aids can only provide limited relief. In addition to hearing damage, noise also causes increased blood pressure as well as disorders of the nervous and digestive system [2]. The WHO estimated resulting costs at $750 billion worldwide in 2016 [3]. On top there are production downtime costs that cannot be measured directly as well as declining labour productivity, which by far exceeds the known expenses [4].

Safety and protection at the workplace

Noise is also of great importance for occupational safety: A loud working environment leads to acoustic warning signals not being heard in time or not at all. According to the Federal Ministry of Labour and Social Affairs (BMAS), 28% of men and 10% of women work »under noise« [5]. In Germany a total of 5 million workers are exposed to harmful noise that can endanger their hearing [6]. Limiting values are regularly exceeded, so that hearing protection devices and preventive medical check-ups to detect incipient hearing damage are mandatory.

Our vision for a better quality of life

With recalm we want to consistently apply and develop ANC technology further. Our goal is to better protect people against noise, associated dangers and risks at their workplace. Our initial focus lies on the health and safety of the particularly vulnerable group of construction and agricultural machinery operators. Reducing noise pollution preserves their hearing, prevents stress and related illnesses. recalm increases the overall performance and thus improves the work and quality of life of our users.


True strength comes from calmness

recalm reduces annoying and harmful noises for humans through targeted anti-sound by up to 75% in the frequency range <500 Hz. First, microphones pick up sound waves from a primary source, e.g. loud engine noises. Our developed ANC software then generates signals with opposite polarity to this source. These are emitted as counter-noise by our ANC system, which is attached to the headrest. These anti-noise signals neutralize disturbing noises for the human hearing by “destructive interference”. This means that both sound waves cancel each other out and a wave with a much smaller residual amplitude is created.

Adaptive, preventive and selective

For reasons of safety and wearing comfort, all existing forms of hearing protection and noise cancelling headphones do not solve this problem. Our algorithm selectively reduces annoying and damaging (machine) noises for humans. At the same time, acoustic signals remain audible, e.g. while driving backwards, instructions from the foreman, walkie-talkies, mobile phones and radio (selective). The recalm software acts adaptively: Once the machine operator opens the driver‘s door or a window, the system adapts within seconds to the changed noise characteristics.

Focus on the human being

The long-term goal of recalm is to improve the well-being of its users. We intend to serve their health, safety and performance, and not the short-term compliance with noise limits. In addition to potential sales growth and cost savings our technology offers employers promising opportunities in terms of attractiveness and differentiation in the recruitment and retention of skilled professionals.


User-friendly installation and operation

recalm offers the click-on solution for the headrest – coming as original equipment or technical upgrade. Ready for commissioning by the machine operator in just a couple of minutes. Eliminates the need for headphones and hearing protection. Once installed, the product harmonizes with the conditions of the headrest and cabin. Easy and intuitive control via the user’s own smartphone. All settings and individual user profiles are managed through mobile app and Bluetooth.

Innovation with strong performance

The current range of applications includes vehicle cabins for construction and agricultural machinery. Thanks to recalm’s ergonomic workplace machine and equipment operators can be exposed up to 100 times longer to noisy environmental conditions without suffering hearing damage.


recalm GmbH was founded in 2017 by Marc von Elling, Martin Guenther, Lukas Henkel and Ralf Ressel. Marc had the idea for active noise reduction in his apartment in Hamburg-Altona at the beginning of 2016. Regularly exposed to the volume of the nearby fish market and Reeperbahn, he first envisioned eliminating noise at the touch of a button and without headphones in order to reduce stress and noticeably improve the quality of life.

It soon turned out that he was not alone with his problem. Parallel to his everyday work he began to do research on various algorithms. In the same year Lukas and Martin joined as co-founders and Ralf as an experienced mentor. Together they developed the first prototype and successfully went through a number of private and public funding programs.

The recalm team has doubled since then. Together with our partner companies and investors we are working intensively on the market maturity of the first fully functional ANC device that can be operated via mobile app in driver cabs of construction and agricultural machinery.


Marc von Elling
Co-Founder and Managing Director
Lukas Henkel
Co-Founder and Managing Director
Ralf Ressel
Co-Founder and Mentor
Sebastian Gehrke
Design Engineer
Julius Häuslein
Design Engineer
Sven Höber
Design Engineer
Eike Schwarzwald
Design Engineer
Benedikt Zimmermann
Design Engineer
Minh Tung Bui
Design Engineer
Cem Cinar
Design Engineer
Anna von Spreckelsen
Design Engineer
Dariush Fardanesh
Design Engineer
Hans von Westernhagen
Sales Manager
Sophia Brand
Internship Entrepreneurship

Partners and Supporters



recalm GmbH
Harburger Schloßstraße 6–12
21079 Hamburg

+49 40 76629 -3882

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