Noise masking system and method in image forming apparatus

摘要

A noise masking system in an image forming apparatus such as a laser beam printer or a copying machine having a drive mechanism acting as a noise generation source during operation, the noise masking system comprising a masking sound generator for generating a sound to mask the noise and masking sound control device which controls the masking sound generator to generate a masking sound of a frequency range including a main-component frequency of the noise. The masking sound thus generated is of a frequency range from a lower-limit frequency to an upper-limit frequency in a critical band of the main-component frequency of the noise. The noise masking system masks noise without decreasing the sound pressure of the noise.