Annoyance perception of complex multi-tone noise signals in both harmonic and inharmonic structures within the built environment

Abstract

Assorted building mechanical systems generate tonal components within the background noise of built environments. In most cases, this type of noise includes multiple tones in harmonic or inharmonic structures rather than a single tone. However, there is limited information on the comprehensive annoyance caused by multiple tones as perceived by human occupants. Two current standards, ISO 1996-2 and ANSI S1.13, propose calculation methods to address tones in noise, but those methods only analyze the tones individually. This paper aims to investigate how each tone contributes to overall annoyance perception when complex tones are present in background noise. Noise stimuli with five-tone complexes between 125 Hz to 2 kHz were artificially generated for subjective testing. The levels of each tone were randomly adjusted for every trial, and both harmonic and inharmonic structured tone complexes were utilized. Ten musically trained subjects participated in the subjective test involving paired comparisons. Each participant was asked to choose which noise stimulus is more annoying between two noise signals. Perceptual weighting analysis is applied to the results to compute a spectral weighting function for overall annoyance. The performance of the derived spectral weighting function is examined against annoyance ratings of actual building mechanical noises.