Loudness evaluation of sounds transmitted through walls—basic experiment with artificial sounds

Abstract

A basic psycho-acoustic experiment was performed in order to establish a reliable method for evaluating insulation properties of building walls against airborne sound. Eleven models were used to represent actual sound insulation characteristics and three models used for incident noises on walls. Results of a four-step hearing test were arranged according to five well-known measures for noise assessment, and Perceived Level ( PL) was found to be the best among them for assessing the loudness of the sound transmitted through walls. In addition, arithmetic mean values of the sound pressure levels in octave bands from 63 Hz or 125 Hz to 4 kHz were examined. It was found that such simple measures have an unexpectedly high correlation with the loudness, surpassing even the PL. This suggests that the arithmetic mean value of the sound transmission losses in octave bands is a good single-number measure for rating the airborne sound insulation performance of walls.