Systematic review of the evidence on the effect of environmental noise on cognition

This paper reports a review of the strength of the evidence for the effect of environmental noise on cognition, carried out for the World Health Organisation Europe. Using a systematic review methodology, quantitative non-experimental studies of the effect of environmental noise exposure on child and adult cognitive performance published up to June 2015 were sought from citation databases. A total of 34 papers were identified, all of which were of child populations. 82% of the papers were of cross-sectional design, with fewer studies of longitudinal or intervention design. The most commonly reported cognitive outcomes were tests of reading and oral comprehension as assessed by direct testing (41%) or Standardised Achievement Test (SATS) data (38%). Studies also assessed short-term and long-term memory (35%); attention (38%); and executive function (26%). The strength of the evidence varied across outcomes. There was a lack of longitudinal and intervention studies across most outcomes, and studies examining exposure-effect relationships are required across the cognitive outcomes. Studies of adult populations remain a priority for future research. The lack of evidence for noise effects in some cognitive domains does not necessarily mean that there are no effects: rather, that more studies are required.