Audible Noise Suppression
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-27
A technique is described whereby the audible noise produced from noisy devices, such as fans and disk drives as used in personal computers, is suppressed. The concept incorporates out-of-phase waveform technology for the cancellation of the audible noise. Generally, audible noise produced from noisy devices, such as fans and disk drives, is present at a relatively constant low frequency for a defined period of time. As a result, the periodicity of the dominant component of the noise can be used to produce an out-of-phase signal so as to cancel out most of the noise. The concept described herein incorporates a self-calibrating assembly of electrical components so as to produce the cancelling out signal.