Date of this Version
Hathaway, A. H. (2013). Effects of Time Varying Background Noise Conditions On Human Perception and Performance (M.S. Thesis). University of Nebraska - Lincoln.
This thesis was designed to study the effects of changing noise conditions on human perception and performance. In two phases, participants were exposed to a number of noise conditions and their performance on an arithmetic task involving short-term memory was monitored and their subjective perception of noise conditions was collected via questionnaires.
In the first phase, participants were tested while being subjected to RC-29(H) and RC-47(RV) conditions created by broadband noise fluctuating on different time intervals, resembling the changing noise conditions potentially found in modern HVAC systems. These intervals varied from two minutes to ten minutes. Results show a significant relationship, p
In the second phase, participants were tested while being exposed to four different levels of the noise bursts presented with or without an associated rattle noise, resembling low-level sonic booms potentially produced by newly developed supersonic aircraft as experienced in the built environment. The noise bursts exhibited peak A-weighted sound pressure levels (LApk) ranging from 55 to 70 dBA. Few statistically significant relationships were found in relation to task performance; however, statistically significant relationships were seen in most of the subjective perception ratings. Both the 70 dBA and 65 dBA were rated statistically significantly more annoying than the 55 dBA and 60 dBA bursts alone as well as the 55 dBA burst plus rattle, implying that noise bursts at or above 70 dBA, and potentially at or above 65 dBA, with accompanying rattle should be avoided. At lower levels, the addition of rattle in this lab study did not result in much difference. It is suspected that rattle occurring in a person’s personal living or work space could be considered to be more annoying. Field studies are suggested for future work.
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