It’s no news to anyone that general aviation airplane cabins are loud. After all, the engines have minimal mufflers, the thin aluminum skins vibrate like a drum, the exhaust exits ahead of the cabin, the tail cone is shaped like a loudspeaker aimed at the occupants, the windows are thin, the prop tips are moving at a high percentage of Mach and the manufacturer’s sound insulation is minimal.
How noisy are they? OSHA did extensive sound intensity testing and came up with a time-weighted average of just over 86 decibels (dBA). However, it was examining the work environment of flight instructors, so nearly half of the testing was done at less than 60 percent power. Testing by Dennis Wolter of Air Mod, an aircraft refurb and renovation shop on Clermont County Airport in Batavia, Ohio, in a number of airplanes revealed an average of 92 dBA at the pilot’s ear at 70 percent power.