Quantifying the Effect of Noise on Cognitive Processes: A Review of Psychophysiological Correlates of Workload

Dogs Barking and Babies Crying: The Effect of Environmental Noise on Physiological State and Cognitive Performance

Objective

The exposure to some environmental sounds has detrimental effects on health and might affect the performance in cognitive tasks. In this study, we analyze the effect of the neighborhood noises of a baby crying and dogs barking on the autonomic response and cognitive function.

Materials and methods

Twenty participants were exposed, in separate sessions, to white noise, a baby crying, a small dog barking, and a large dog barking. During each session, heart rate, skin conductance, reaction times, spatial memory, and mathematical processing measures were taken throughout time.

Results

The sounds of a baby crying and dogs barking led to significantly higher heart rates and skin conductance levels as opposed to exposure to white noise. Results were not as consistent with exposure to barking as they were to the baby. Exposure to the baby crying and dogs barking led to faster reaction times, possibly due to a facilitation by the autonomic system activation. No significant effects on spatial memory were found. Conversely, participants performed worse and slower in a mathematical task when exposed to the dog and baby sounds, than when exposed to control noise.

Conclusion

Exposure to the sound of crying babies and dogs barking leads to increased sympathetic response and decreased cognitive ability, as compared to exposure to control sounds. Special attention should be paid to the mitigation of exposure to these types of noises.

Traffic Noise at Moderate Levels Affects Cognitive Performance: Do Distance-Induced Temporal Changes Matter?

Urbanization leads to an increased demand for urban housing, which can be met by building dwellings closer to streets. Regulations often limit equivalent sound pressure levels which do not account for changes in time structure that occur when decreasing the road distance. This study investigates the effect of such temporal changes on subjective workload and cognitive performance. A group of 42 participants performed a continuous performance test as well as a NASA-TLX workload test under three different sound conditions, i.e., close traffic, far traffic, both with the same equivalent sound pressure level of LAeq≈40 dB, and silence. Additionally, participants answered a questionnaire regarding their preferred acoustic environment for concentrated working. Significant effects of the sound condition on the multivariate workload results as well as on the number of commission errors in the continuous performance test were found. Post hoc tests showed no significant differences between the two noise conditions, but there were significant differences between noise and silence. This indicates that moderate traffic noise levels can influence cognitive performance and perceived workload. If there is a difference in the human response to road traffic noise with constant LAeq but different time structures, the used methods are not suitable to detect them.