Mechanisms of Sound Production
A moving aircraft including the jet engine or propeller causes compression and rarefaction of the air, producing motion of air molecules. This movement propagates through the air as pressure waves. If these pressure waves are strong enough and within the audible frequency spectrum, a sensation of hearing is produced. Different aircraft types have different noise levels and frequencies. The noise originates from three main sources:
- Aerodynamic noise
- Engine and other mechanical noise
- Noise from aircraft systems
Read more about this topic: Aircraft Noise
Famous quotes containing the words sound and/or production:
“But those rare souls whose spirit gets magically into the hearts of men, leave behind them something more real and warmly personal than bodily presence, an ineffable and eternal thing. It is everlasting life touching us as something more than a vague, recondite concept. The sound of a great name dies like an echo; the splendor of fame fades into nothing; but the grace of a fine spirit pervades the places through which it has passed, like the haunting loveliness of mignonette.”
—James Thurber (1894–1961)
“Perestroika basically is creating material incentives for the individual. Some of the comrades deny that, but I can’t see it any other way. In that sense human nature kinda goes backwards. It’s a step backwards. You have to realize the people weren’t quite ready for a socialist production system.”
—Gus Hall (b. 1910)