Title: Design and Analysis of an Active Noise-Canceling Headrest
Speaker: Jacob Bean, PhD candidate, Virginia Tech
Date: Thursday, March 15, 2018
Location: NIA, Room 142
Meeting number: 643 633 072
Audio connection: +1-855-749-4750 US TOLL FREE; +1-415-655-0001 US TOLL
Abstract: Excessive noise and vibration levels in aircraft, rotorcraft, launch vehicles, and other aerospace vehicles may create harsh acoustic environments inside the vehicle. In some extreme cases, military applications being a prime example, hearing damage can occur due to the high noise levels associated with certain vehicles. Noise canceling headsets have been proven an effective solution to this problem, although in certain instances their use may not be safe or feasible.
In this work, an active noise canceling headrest, or active headrest, is explored as an alternative solution to noise canceling headphones/headsets. An active headrest uses microphones and loudspeakers, typically located non-intrusively behind the head of the seat occupant, to reduce the ambient noise levels in the vicinity of the head and create a comfortable acoustic environment. A thorough investigation of the viability of such a system in a practical vehicle is assessed through the use of theoretical analysis, finite element modeling, and real-time performance experiments. Performance predictions generated using the finite element model were verified by performing real-time experiments, thus providing a level of confidence in additional predictions for alternative headrest geometries/configurations. Factors such as loudspeaker and microphone placement, head movements away from the nominal position, primary acoustic field characteristics, and choice of control strategy are all found to heavily influence the performance of an active headrest. Real-time experiments were performed in anechoic and reverberant sound fields and it is found that the noise canceling capability of the active headrest worsens in reverberant sound fields as compared to free field conditions.
Bio: Jacob received his B.S. in aerospace engineering in 2013 from Virginia Tech. Since then, he has been pursuing his Ph.D. also in aerospace engineering under a graduate research assistantship at the National Institute of Aerospace, with Virginia Tech as his home university. This assistantship afforded him the opportunity to work with the Structural Acoustics Branch at NASA Langley Research Center throughout his tenure as a graduate student. As a student, Jacob served as Chair of the AIAA Student Chapter at the National Institute of Aerospace for 3 years. After graduating in May, 2018, Jacob will be moving to Michigan to work as a Senior Engineer at Qualcomm Technologies, Inc.