Formerly, Active Noise Cancelling (ANC) solutions were offered only in headphones. Now, together with start-up recalm of Hamburg, at bauma 2019 Fritzmeier CABS showed a system that offers drivers considerably more comfort and freedom. “Like others, recalm reduces noise by means of counter-noise,” explains Lukas Henkel, co-founder and COO at recalm. “But we put it in the headrest. This protects drivers from noise without blocking off the outside world. For example, they can still communicate by radio as before without any problems.”
Construction machine operators are exposed daily to critical noise levels, and the risk of hearing loss is acute. Prolonged exposure to noise also impairs performance and concentration, which can lead to errors and safety risks. The recalm company has an all-new solution for this problem, which could be seen at bauma in a Fritzmeier cab. Henkel explains the technology behind it: “A microphone picks up the low-frequency engine noise. Our software generates phase-shifted sound waves in real time and outputs them through loudspeakers. These cancel out unwanted noise to reduce the noise level by 10-20 dB in the range up to 500 kHz. In future up to 1 kHz will be possible.”
Currently the recalm system does not detect the operator’s head position, but instead projects the quiet zone to one of three different areas predefined by the system. The user can switch between them using an app (for example, drivers who prefer to sit with their head leaning back would choose Zone 1). In the next development step, sensors will detect the position of the driver’s head so that the quiet zone is projected precisely to the user.
The machine operator is thus protected from noise but not restricted in freedom of movement and communication, and is able to communicate with others completely normally. “Machine operators have more and more complex jobs,” says Henkel. “So it’s more and more important to design cabs around the operator’s needs and do everything possible to make their job as comfortable as possible.” The recalm system reduces noise by a subjective 75%, so that a machine operator can work much longer without risking hearing damage. The important matter of attracting skilled workers is an added benefit. The higher the operator comfort, the easier it is to get and keep qualified employees.
The system can either be integrated directly into the headrest or retrofitted as a clip-on version.