Noise & Helicopters

Noise is the garbage of mechanical energy. Noise is a part of the small percentage of available energy which, like the waste from our kitchens, cannot easily be eliminated or reclaimed. Noise energy loss represents, in general, less than one-tenth of one percent of the available energy used in the machines which produce the noise. A reasonably well-designed machine can therefore gain only small increments of efficiency by design for the nonexistence of sound. The research, engineering, and production costs for the complete elimination of noise at the true noise source are far in excess of the efficiency profit obtainable from such an effort, when only the efficiency of an individual machine is considered. We can probably never justify the elimination of noise by component efficiency arguments.