Subjective and objective evaluation of water-supply and drainage noises in apartment buildings by using a head-mounted display

Abstract

To provide a novel methodology of indoor-noise evaluation by using virtual reality (VR) technology, an auditory test was conducted on water-supply and drainage noises of apartment buildings in different environments, including VR, and the influence of the head mounted display (HMD) was investigated. First, through the analyses of sound pressure level, spectrogram, and sound quality (SQ) for the noise sources of water supply and drainage measured on site, the changes were checked according to time. Furthermore, by targeting the sounds of toilet on the floor immediately below, the allowable endurance limit and annoyance level were evaluated by changing LAeq in four environmental set-ups: headphone, speakers, headphone and HMD, and speakers and HMD. As a result, between the use or disuse of HMD, the allowable endurance limit and annoyance level showed 6% and 8% differences on average, respectively, showing that their sound-pressure levels for 50% annoyance level differed by 2.2 dBA, and they were evaluated as most sensitive in the speakers and HMD setup. In the semantic differential test result, the scale value was evaluated as high owing to the increase in visual information through HMD. In addition, the comparison of respective noise sensitivity groups confirmed that the influence of HMD was very large. Therefore, in this study, it was confirmed that to evaluate the environmental noises in residences under a test laboratory condition, the method of using speakers and HMD simultaneously was effective for implementing a setup similar to actual on-site evaluation.