Engines make noise. Crew—especially when they’re trying to hold a conversation, sleep, or just relax—don’t like noise. The solution? Isolate the crew from the engine noise and vibration. In this update of our May 1, 1993 report, 10 sound-attenuating products are tested and ranked.

Noise and vibration are inseparable. Noise exists because vibration causes variations in the air pressure that reaches the ear. This is perceived as sound. An effective control deals with both the vibration and the airborne noise.

Noise levels are measured in decibel units, usually referred to as dBA (the A denoting that the measurement is adjusted for the frequency response of the human ear, rather than the total…