Measurement of drum sound (NT TR 573)

Abstract

The interest in the effect of background noise on our health and capacity for work has increased. One of the disturbing factors in office spaces, schools etc. is the drum sound, especially when the flooring consists of thin wood parquet or laminate. Drum sound is the noise that appears when an object, e.g. a foot, hits the flooring in the same room as the receiving ear. The consumers increasing demand on floorings with improved drum sound properties has made the industry interested in finding better products. As better products are developed, a harmonized measurement method to present the performance of the floor to the market is needed. The objective in this project is to test two objective (instrumental) methods and based on the raw data of these methods apply different measures such as A-weighted sound pressure level and loudness to check the correlation of these to results from listening tests. The objective measurements are made at Engineering Acoustics, LTH, Sweden and at DELTA, Acoustics and Vibration, Denmark. The listening tests are performed by Engineering Acoustics. The question of the listening test regarded perceived disturbance and perceived loudness. It is seen that the standard tapping machine without any additional cover cannot be used on all types of floorings without further restrictions due to the inherent noise from the machine itself. The measurement set-ups used by DELTA and LTH result in similar agreement to the listening test and the objective measures loudness and Cweighted sound pressure level show best agreement to the listening test result.