ACCEPTABLE LEVELS OF SOUNDS WITH DIFFERENT SPECTRAL CHARACTERISTICS DURING THE PERFORMANCE OF A SIMPLE AND A COMPLEX NONAUDITORY TASK

Four groups of 24 subjects were exposed to 100 and 1000 Hz tones or broadband noise in a sound chamber. During exposure the subjects were engaged in an easy reaction time test or a difficult test of logical thinking. For each exposure and work the subjects adjusted the noise to two annoyance levels, defined by their interference with task performance. During the simple reaction time task significantly higher sound pressure levels were accepted (c. 6 dB) than during the reasoning test. At 1000 Hz, much lower levels (c. 22 dB) were accepted of the tone than of the broadband noise. At 100 Hz a non-significant trend in the opposite direction was obtained. The results imply that the A-weighting procedure leads to an overestimation of low frequency tones and an underestimation of the low frequency band noise with respect to tolerance levels during work. © 1993 Academic Press limited.