Acoustic characterization of in-room footfall noise

Existing literature concerning footfalls is primarily focused on its transmission between spaces, such as a floor/ceiling's Impact Isolation Class. Studies at the University of Hartford measured in-room sound power spectra produced by footfalls on twelve different floor surfaces using human subjects and a standard tapping machine. Within a qualified reverberation room, fourteen male and female subjects walked on the floor surfaces while wearing three different types of footwear: leather-soled shoes (hard), rubber-soled shoes (medium), and sneakers (soft). Sound power spectra and vibratory signatures were measured in 1/3 octaves according to the ISO 3741 standard. A tapping machine was also used on each floor profile using both standard drop weights and with cored samples of the same shoe soles attached to the bottom of each weight. The data for each floor profile produced averages by shoe type along with corresponding 95% confidence intervals. Correlations between sound power and vibratory spectra produced with human walkers versus tapping machine (both with and without “shoes”) were investigated, resulting in correction factors to model machine tapping as human footfalls. [Work supported by The Paul S. Veneklasen Research Foundation.]