Publication Date


Document Type


First Advisor

Liu, Lichuan

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Electrical Engineering


In an intensive care unit (ICU), there are many kinds of noises. For example, patients suffer from the noise which is made by doctors’ or nurses’ activities and devices of ICU can cause some problem too, like stress and losing ability of hearing. In this thesis, we propose to use active noise control (ANC) systems to reduce the high noise level for intensive care unit (ICU) residents.

At first, conventional multiple channel ANC system has been proposed to reduced noise. And then a new method has been proposed which is Auxiliary Filter Based Virtual Sensing (AF-VS) to compensate defect of conventional multiple channel ANC system. Instead of achieve maximum noise cancellation at the error microphone locations, this technique can move quiet zone to the virtual sensor locations which are hard to place actual physical sensors. Sinusoidal noise, white noise and recorded ICU noise have been used as primary noise sources to validate the system’s noise cancellation performance. Then computer simulation results in Matlab prove that the proposed system can reduce ambient noise level around patient’s ears. Finally, real-time experiment will be test for both conventional multi ANC system and multi AF-VS ANC system.


83 pages




Northern Illinois University

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