In cruise flight, passengers may be exposed to considerable noise. But how does the noise get from the source to the passenger? In two ways. Airborne sound radiates from a source of noise, such as the jet engines, and is perceived by passengers in the cabin. In addition, engine vibrations spread through the aircraft structure reaching the cabin. Similar to loudspeakers, the vibrating surfaces of the cabin in turn emit airborne sound, which is perceived by passengers as noise.
In the Department of Structural Dynamics and System Identification of the Institute of Aeroelasticity, DLR addresses the issue of structure-borne cabin noise.