Balm for the ears

Optimizing fan noise. Noise pollution is a serious problem. While electromagnetic emissions from electronic devices have been greatly reduced over the past decade, noise has only recently become an issue. This is because noise limits people’s ability to work under pressure and concentrate, and is harmful to health if exposure is prolonged.

Why do fans make noise? To answer this question, one must first distinguish between airborne and structure-borne sound. Both sound events make themselves felt with different weighting; they must be optimized separately …