So-called “crossbars” are a great relief for many residents of noisy cities. These are new buildings that close gaps between rows of houses to keep street noise out.
In the Middle Rhine Valley, as many as 600 trains thunder over the tracks in a given day. In recent years, so-called whisper brakes have been installed on many rail cars to reduce rail noise. But for local residents, it’s not enough. They are calling for further “quiet” measures.

The start-up “recalm” wants to use “antisound” to reduce noise in mining vehicles. Until now, drivers had the roar and hum of the machines in their ears for eight hours a day, all but guaranteeing hearing loss. With the new high-tech system, low frequencies are reduced, leading to 50% less noise.
Owls are silent. That’s why they are the perfect model for Professor Jan Werner Delfs of the German Aerospace Center (DLR) in Braunschweig. Along with a colleague, the acoustics expert and aerodynamics engineer is researching the art of silent flight – and thus the possibility of making aircraft fly more quietly.

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