Effect of temporal decay on perception of heavy-weight floor impact sounds

This study investigates the effect of temporal decay on perception of heavy-weight floor impact sounds through auditory experiments. Heavy-weight impact sounds were recorded in apartment buildings with a box-framed type reinforced concrete structure using a rubber ball. Temporal decay was quantified by using the decay rate (DR), defined as the sound pressure level (SPL) decrease per second [dB/s], and the distribution of DR for heavy-weight impact sounds was calculated. An auditory experiment was conducted in order to examine the just noticeable difference (JND) of DR, which was determined by the criteria of 75% correct answers by subjects. It was found that the JND of DR is around 11 dB/s. Based on the distribution and JND of DR, another experiment was conducted to investigate the effect of DR on annoyance perception of heavy-weight floor impact sounds in relation to the level differences. The results indicate that SPL and DR significantly influence annoyance perception; the scale value of annoyance increases with decreasing DR and increasing SPL. It was also found that the degree of satisfaction with regards to impact sounds can be improved by increasing DR, by controlling the sound field of the receiving room.