Next Article in Journal
Low Cost Omnidirectional Sound Source Utilizing a Common Directional Loudspeaker for Impulse Response Measurements
Next Article in Special Issue
Impact and Control of Reflected Noise from an Overpass Bottom
Previous Article in Journal
Study on Hysteresis Model of Welding Material in Unstiffened Welded Joints of Steel Tubular Truss Structure
Previous Article in Special Issue
A New Method for Active Cancellation of Engine Order Noise in a Passenger Car
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessArticle
Appl. Sci. 2018, 8(9), 1702;

Noise-Canceling Office Chair with Multiple Reference Microphones

Department of Measurement and Information Systems, Budapest University of Technology and Economics, 1111 Budapest, Hungary
These authors contributed equally to this work.
Author to whom correspondence should be addressed.
Received: 31 August 2018 / Revised: 14 September 2018 / Accepted: 16 September 2018 / Published: 19 September 2018
(This article belongs to the Special Issue Active and Passive Noise Control)
Full-Text   |   PDF [6147 KB, uploaded 19 September 2018]   |  


Office employees are exposed to acoustic noise, especially in an open office environment. Passive or active headsets sufficiently reduce the level of noise, but their long-time wear is uncomfortable. The paper presents an active headrest system built into a chair. Feedforward control is utilized with multiple reference microphones, and flexible gooseneck microphones serve as error sensors. The reference sensors surround the chair, allowing the suppression of sound waves arriving from any direction. The concept of multiple reference control has been tested by extensive experiments showing that multiple reference signals help to increase the suppression in normal rooms where reverberation occurs, even if only one noise source is present. The preliminary experiments are completed by a series of simulations aiming to explore the zones of quiet at the user’s ears. The paper introduces the construction details of the noise-canceling chair: The two loudspeakers are controlled by the signals of two error microphones and four reference signals. The controller is based on the normalized filtered error least mean squared algorithm, implemented on an Analog Devices ADSP-21262 signal processor-based hardware. Experimental results are reported that show the efficient suppression of tonal, as well as broadband disturbances. View Full-Text
Keywords: active headrest; office chair; multiple reference feedforward control; ELMS algorithm active headrest; office chair; multiple reference feedforward control; ELMS algorithm

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Sujbert, L.; Szarvas, A. Noise-Canceling Office Chair with Multiple Reference Microphones. Appl. Sci. 2018, 8, 1702.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Appl. Sci. EISSN 2076-3417 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top