Some problems and design factors concerning noise in motor-driven home appliances

DURING RECENT YEARS, the ratio of material to labor cost of mass-produced products has been increasing, mainly owing to the more effective use of automatic processes. In turn, this has stimulated efforts toward producing greater output per pound of material in such items as small motors, and toward greater utility per pound in such products as home appliances. This trend, along with the shifting of appliances from basement to kitchen or first-floor utility areas, brings the reduction of objectionable or undesirable sound (referred to as noise) into the forefront as a major design factor. The purpose of this paper is twofold. First, the over-all appliance noise problem in general terms will be discussed and, second, the problem of reducing that portion of noise contributed by the motor will be discussed specifically.