Combined transportation noise exposure in residential areas

Peter Lercher*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review


In everyday life people are simultaneously exposed to several sound sources, which emerge from background soundscapes of considerable variability due to building layouts, residential pattern, topography, meteorology, and lifestyle. In contrast, noise regulation, planning, and control treat the sound environment by separating it into pieces and describe it by a one-number indicator. This practice ignores the possibility of any effect modification (by inhibition, partial or full additivity, or synergism). This effect modification can take place not only between sound sources (multisource issue) but also with simultaneously occurring environmental factors (vibration and air pollution) from the same source or through other contextual factors (multistressor issue). What people know about auditory perception of combined sound exposure mainly rests on experimental work using short-term loudness judgments in repeated designs in controlled settings. Recent psychoacoustic experiments did not find full support for the most prevalent models in practice (e.g., simple energy summation), when the context of the assessment is more carefully distinguished (sound heard within combined sound or alone). The findings are difficult to compare with field studies where long-term judgments of annoyance take place in the immediate context of the subject’s living environment. The combined noise paradox is such a finding. It describes the phenomenon that total annoyance is often judged equal or even lower than the dominant source alone. Some call it compromise judgments suggesting them to result from ambiguous questions or misinterpretations of the frame of reference when total annoyance should be assessed. In experiments, compromise judgments were observed mainly with unequally loud and time-separated sounds. But also increases in total annoyance have been observed in the field studies. Although masking partly explains lower annoyance, higher annoyance due to equally loud sources is less well understood. Further effect modifications have been observed with simultaneously occurring vibrations (trains), low-frequency annoyance, and tonal and impulsive components of heterogeneous sound sources such as those from industry. The larger annoyance effects observed can vary in terms of decibel equivalents between - 3 and + 15 dBA. The highest values are associated with impulsive noise and low background noise context (high signal to noise ratio). Eventually, air pollution and other contextual factors can further contribute to total annoyance. Incomplete consideration of effect modifications in environmental risk assessments will lead to errors in planning and less than optimal noise control.

Original languageEnglish
Title of host publicationEncyclopedia of Environmental Health
EditorsJ Nriagu
PublisherElsevier BV
Number of pages18
ISBN (Electronic)9780444639523
ISBN (Print)9780444639516
Publication statusPublished - 1 Jan 2019


  • Air pollution
  • Aircraft noise
  • Annoyance
  • Auditory perception
  • Combined effects
  • Combined noise paradox
  • Cumulative impact assessment
  • Environmental health impact assessment
  • Environmental noise
  • Impulse noise
  • Loudness
  • Low-frequency noise (LFN)
  • Mixed sound sources
  • Railway noise
  • Road traffic noise
  • Soundscape
  • Vibration

ASJC Scopus subject areas

  • Environmental Science(all)

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