Speaker
Description
This study presents a detailed analysis of how sound character influences the annoyance ratings of heat pump noise, based on data from a listening experiment conducted as part of the IEA/HPT Annex 63 on Placement Impact on Heat Pump Acoustics. This large-scale listening experiment was originally designed to investigate the impact of heat pump placement in residential environments, considering factors such as the number of units, their spatial arrangement, operating conditions, background noise, and noise barriers.Using this dataset, the present work performs a secondary analysis focusing on perceptual sound characteristics. In particular, it examines the hypothesis that loudness provides a more suitable description of annoyance than conventional sound level metrics, including A-weighted sound pressure level. In addition, the study explores whether further psychoacoustic attributes, such as tonal components, roughness, and sharpness, contribute to annoyance beyond what can be explained by level or loudness alone.To this end, sounds are systematically compared under controlled conditions of similar level or loudness, allowing the influence of specific sound characteristics to be investigated. The dataset, while originally developed for a different research focus, provides a suitable basis for an initial assessment of these perceptual factors.The results provide indications that both hypotheses are supported: perceived loudness appears to be more closely related to annoyance than level-based measures, and additional sound characteristics further influence listener responses. These findings highlight the importance of considering both the intensity and the character of sound when investigating heat pump noise annoyance, while also pointing to the need for dedicated studies to confirm these effects.