Subjective and objective rating of the sound insulation of residential building façades against road traffic noise.

Sound insulation in a building façade plays a key role in the control of road-traffic noise. Façade performance can be described using various internationally standardized single-number quantities (SNQs) with different frequency weightings. The purpose of this study was to evaluate how 25 different SNQs explain the subjective ratings of spectrally different road-traffic sounds transmitted through a façade. Forty-three participants took part in a psychoacoustic laboratory experiment. The task was to evaluate five spectrally different road-traffic sound types transmitted through 12 simulated façade constructions. The participants rated both the loudness and the annoyance of 60 sounds. The playback levels were between 12 and 46 dB L Aeq , covering the essential range of road-traffic noise usually measured inside residential dwellings. Linear correlations were determined between the SNQ values of the façades and the subjective ratings. R w + C 50-3150 explained the subjective ratings best when the five sound types were equally considered. It was also the most suitable SNQ for the standard road-traffic spectrum of ISO 717-1. The results of this study can be useful in the development of future standards.