Department of Mechanical Engineering

Relating Indoor Noise Criteria Systems to Human Performance and Perception

 

Erica E. Bowden
Architectural Engineering Program, University of Nebraska - Lincoln

Abstract:
A series of studies examining human response to heating, ventilating, and air-conditioning (HVAC) systems-induced background noise are being conducted at the University of Nebraska. The primary objective is to evaluate several noise criteria methods commonly used in architectural acoustics and HVAC systems design, including Noise Criteria (NC), Room Criteria (RC), A-weighted Equivalent Sound Pressure Level (LAeq), and others. An on-going debate exists in the acoustical community over the appropriate use of these criteria under the variety of ambient noise situations encountered in the built environment. This project quantitatively relates these criteria to human task performance and noise perception under a variety of HVAC systems-induced background noise conditions. The effects of various qualities of sound are examined, including loudness, tonality, spectral balance, and time variance. Results suggest that task performance is significantly affected by occupant perception of noise, but this relationship is not fully demonstrated by the criteria systems analyzed. Additionally, some discrepancies in criteria ratings of spectral quality (rumble, roar, hiss, etc.) and subjective perception have been identified. The results are being used by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) subcommittee on indoor noise criteria to revise their preferred method to account for these discrepancies. Other research Ms. Bowden has been pursuing on speech intelligibility evaluation methods and hospital noise will also be highlighted. [Dissertation research supported by ASHRAE, INCE, and the UNL Center for Building Integration]

Ms. Erica Bowden is currently pursuing her Ph.D. in Architectural Engineering (AE) at the University of Nebraska, with a focus in building acoustics and noise control. She holds a Bachelor’s degree in AE with a focus on acoustics and HVAC from Kansas State University, along with a minor in music. Ms. Bowden has industry experience in both mechanical systems engineering at Leo A. Daly (Omaha, NE), and in acoustical consulting at Kirkegaard Assoc. (Chicago, IL), and Pelton Marsh Kinsella (Dallas, TX). She has presented several papers through the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE), the Acoustical Society of America (ASA), and the Architectural Engineering Institute (AEI). Ms. Bowden recently chaired a special session on indoor noise criteria at a joint meeting of the ASA and the Institute of Noise Control Engineering (INCE). She was recently awarded the ASA F. V. Hunt Postdoctoral Research Fellowship to pursue hospital noise research in Sweden.

For questions, contact Charlene Kravinsky (4-0356, cakraviiastate.edu)

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