THE MEASUREMENT OF NOISE AND VIBRATION TRANSMITTED INTO AIRCRAFT CABINS

The types of measurements that are made to design and evaluate noise and control treatment for aircraft cabins are reviewed. The sources of cabin noise in jet and turboprop aircraft are described: engine, fan and propeller noise; structure-borne noise; airborne noise; and wind noise. Techniques for reducing cabin noise are discussed. These include engine balancing, the use of vibration isolation mounts to soften the mount, the use of tuned vibration absorbers or shakers and active tonal cabin quieting using speakers as actuators and microphones as error sensors.