Impact sound insulation of floating floors: A psychoacoustic experiment linking standard objective rating and subjective perception

Abstract

Floating floor increases the impact sound insulation of a load bearing concrete slab but very little is known about the subjective perception of impact sounds transmitted through floating floors. A psychoacoustic experiment was conducted to answer three research questions: 1. Is there a subjective benefit to use a floating floor instead of a non-floating floor with natural impact sounds? 2. Do the standardized single-number quantities of impact sound insulation rank the floors in the same order as subjective ranking does? 3. Does the resonance frequency of the floating floor play a role in subjective perception? Four floating floors and two non-floating floors were built in a laboratory where the impact sound insulation was tested using tapping machine and rubber ball. Four natural sound types (basketball bouncing, chair moving, walking with shoes, walking with socks) were presented to the floors and recorded in the furnished room underneath. The recorded sounds were played to 30 participants who rated their annoyance. The answers to the research questions became the following. 1. Floating floor was beneficial over non-floating floor for three sound types out of four. 2. Single-number quantities did not always rank the floors according to the same order as the psychoacoustic experiment did. 3. Lower resonance frequency predicted lower annoyance for most sound types. It seems that the current objective methods of rating the impact sound insulation are not sufficiently predicting the perceived performance of floors. Our results benefit the development of floor constructions and measurement standards.