Activity Interference Caused by Traffic Noise: Experimental Determination and Modeling of the Number of Noticed Sound Events

Abstract

Activity interference is widely considered to be a central mechanism linking exposure to noise and emergence of annoyance. Salient sound events in particular may divert attention from the task at hand, thereby reducing task performance. Sound events caused by traffic noise intruding the dwelling are therefore often found to be a main cause of community noise annoyance. In this work, experimental and simulation results on activity interference caused by traffic noise are compared. On the one hand, an experiment on activity interference by traffic noise was conducted in a realistic setting resembling an at-home situation. Subjects were instructed to read, while being exposed to a combination of road and railway traffic noise. The number of train pass-by events, the distance to the railway track and the emergence of train events above the background noise was varied among subjects. After completion of the reading task, the subjects had to evaluate their perceived disturbance due to passing trains and to report how many trains they noticed in retrospective. On the other hand, a computational model of auditory attention was used to determine the number of train pass-by events that subjects would notice, solely based on the acoustic stimuli used in the perception experiment. Using an optimized stochastic function that simulates the attention spend on the reading activity of the subjects, the model was able to replicate trends found in the empirical results, and estimated the number of noticed train events quite well.2

Assessment Methods and Factors Determining Positive Indoor Soundscapes in Residential Buildings: A Systematic Review

“…Selected studies make use of different study designs, that are laboratory tests [16,[18][19][20][21]24,25,32,34,36,[41][42][43]47] and field campaigns based on socio-acoustic [15,17,22,23,26,28,35,37,39,40,45,46,[48][49][50][51], social surveys [29][30][31]33,38,44], or soundscape assessments [27]. Laboratory studies evaluate testers' response to experimental stimuli in laboratory settings, under controlled conditions.…”

“…As shown in Table 1, laboratory studies typically refer to equivalent levels (L eq ). Exposure conditions made use of auditory stimuli from indoor or outdoor recordings, sometimes filtered to take into account the attenuation provided by the façade, according to the window opening position [36,[41][42][43]. Differently, socio-acoustic surveys typically made use of daily-averaged outdoor levels (e.g., L den , L day ).…”

“…The characterization of auditory stimuli or of the acoustic environments were typically made through monoaural recordings. Anyway, in a few laboratory experiments, auditory stimuli were prepared from binaural [16,32,41], stereophonic [34,47], or ambisonic [42] recordings, in order to better consider the way human auditory system integrate the acoustic environment.…”

A road traffic noise pattern simulation model that includes distributions of vehicle sound power levels

“…When noise events are noticed, they may distract attention and interfere with activities [14][15][16]. Roberts et al [17], too, note that various studies demonstrate anomalies to the accepted view that it is the energy equivalent level that is important for annoyance responses, postulating that it is the pattern of road traffic noise-the presence of noise peak events-that may be critical, also suggesting that response to road traffic noise may be better assessed by some combination of the conventional continuous noise measures with pattern variables such as the number of noise events.…”

From dBA to soundscape indices: Managing our sound environment

“…By convention, L 1 , L 10 , L 50 and L 90 are used to give approximate indications of the maximum, intrusive, median and background sound levels, respectively (Kang, 2007). Effects from contextual as well as psychological factors have been recognised to have an important role (Terroir et al, 2013) in the relationships between incident sound and perceived soundscape--For example, the meaning of sound sources, emergence and regularity of occasional events, number and duration of quiet periods, the amount of greenery that can be visually perceived (Watts et al, 2013), the presence of 'sound marks' and their historical value (e.g. the 'area of clear audibility of Big Ben' has been proposed for Central London), as well as users' social, demographical and behavioural factors and their expectations (Yu and Kang, 2008).…”