Auditory and tactile contributions to the perception of building noise

Abstract

Due to the interdependent relationship between structural vibration and airborne sound, noise in buildings can often be simultaneously heard and felt, but perceptual noise studies usually take place in either the auditory or vibrational domain. This study takes a more holistic approach to the sensory perception of building noise. A subjective experiment was devised in which plausible simulations of 120 combinations of familiar indoor noise events, wall partitions, and receiving room conditions were rendered on a vibrotactile motion platform, incorporating whole-body vertical vibration with binaural audio. Eight normal hearing subjects of varying self-reported noise sensitivity completed a method-of-adjustment task in which they indicated the level of an auditory-tactile stimulus equal in loudness to a purely auditory stimulus. With the addition of floor and seat vibration provided through the motion platform, subjects perceived the auditory-tactile noise event as loud as an auditory-only event having an average 1.7 dB higher sound pressure level. In a second task, subjects rated their overall annoyance with auditory-tactile and auditory-only noise events on a 7-point magnitude scale. The additional annoyance resulting from floor vibration was equivalent to increasing the sound level by 5.7 dB. When annoyance was judged, vibration penalties correlated significantly (p < 0.001) with the spectral similarity of sound and vibration signals (taken as the difference in spectral centroids of auditory and tactile signals), but judgments of loudness generated no such correlation. Results indicate the importance of considering cross-modal interaction in standardized noise metrics, particularly for pervasive low-frequency impact noise in multi-family dwellings.