A new method for predicting the annoyance of transportation noise

The percent of people who are highly annoyed by exposure to similar levels of transportation noise varies considerably from one community to the next. Nonetheless, the federal definition of a “significant” noise impact (Ldn = 65 dB) reflects a one-size-fits-all policy decision that accounts for neither source nor community-specific differences in the annoyance of aircraft, road traffic, and rail noise. Current U.S. noise regulatory policy is based on outdated information and purely descriptive statistical analyses, which offer no explanation for variability in annoyance prevalence rates from community to community. An ISO Working Group is currently considering adoption of a novel method for predicting the annoyance of transportation noise. If this paradigm-shifting approach is adopted as an international standard, it is likely to affect routine methods for predicting and disclosing environmental noise impacts, and to result in changes in federal noise regulatory policy in years to come.