Reducing Leaf Blower Noise: A Product Noise Control Success Story

Leaf blowers are essentially an industrial power tool adapted for light weight and portability. Noise control has not been a traditional hallmark of their design. In fact they inspire intense reactions, numerous complaints, bad press, and attempts at regulation. The roughness and tonality of the 2-stroke engine combines with the tonality of the fan to create a singularly unpleasant sound. As with most products, attempts to "fix" an already-completed design typically results in unacceptable side effects like reduced performance, additional weight, higher parts count, reduced profit margin, etc. Blount International sought in early 2016 to develop a new, from-scratch, battery-powered blower product that could deliver blowing force and volume similar to a motorized blower, while meeting or exceeding industry noise emission guidelines and attaining best in class sound quality. The paper will describe sound quality results for competitive products, rank-order noise emitting elements, fan design factors and their impact on noise emission and battery life, path noise control elements, and their eventual impact on a satisfactory outcome. This product is now proceeding to market, and will hopefully provide significant relief for communities unhappy with leaf blower noise.