Evaluating the effect of prominent tones in noise on human task performance

Abstract

Current noise guidelines for the acoustic design of offices generally specify limits on loudness and sometimes spectral shape, but do not typically address the presence of tones in noise as may be generated by building services equipment. Numerous previous studies indicate that the presence of prominent tones is a significant source of deteriorating indoor environmental quality. Results on how prominent tones in background noise affect human task performance, though, are less conclusive. This paper presents results from recent studies at Nebraska on how tones in noise may influence task performance in a controlled office-like environment. Participants were asked to complete digit span tasks as a measure of working memory capacity, while exposed to assorted noise signals with tones at varying frequencies and tonality levels. Data on the percent correct and reaction time in which participants responded to the task are analyzed statistically. The results can provide guidance for setting limits on the tonalit...