Aircraft noise annoyance in recreational areas after changes in noise exposure: comments on Krog and Engdahl (2004).

When Gardermoen replaced Fornebu as the main airport for Oslo, aircraft noise levels increased in recreational areas near Gardermoen and decreased in areas near Fornebu. Krog and Engdahl [J. Acoust. Soc. Am. 116, 323-333 (2004)] estimate that recreationists' annoyance from aircraft noise in these areas changed more than would be anticipated from the actual noise changes. However, the sizes of their estimated "situation" effects are not credible. One possible reason for the anomalous results is that standard regression assumptions become violated when motivational factors are inserted into the regression model. Standardized regression coefficients (beta values) should also not be utilized for comparisons across equations.