Daniell WE, et al. Noise exposure and hearing loss prevention programmes after 20 years of regulations in the United States. Occup Environ Med 2006;63:343–51.

The authors apologetically report that two noise measurement values were stated incorrectly in the published article. The third paragraph in the “Noise exposure” section of Results should be:

Excessive exposure was more common and higher using the L_eq, which differs from the OSHA L_ave primarily by using a 3 dB rather than 5 dB exchange or doubling rate (fig 1). Overall, 74% of monitored employees had L_eq ≥85 dBA, whereas 50% had L_ave ≥85 dBA; and 38% [not 42%] had L_eq ≥90 dBA, whereas only 21% [not 14%] had L_ave ≥90 dBA.

The statement about these results in the first paragraph of Discussion should be:

The percentage of workers with full-shift exposures over 85 or 90 dBA would have been 1.5–1.8 [not 1.5–3] times higher if noise measurements had used a 3 dB exchange rate rather than the OSHA 5 dB exchange rate.

These corrections apply to similar statements in the Results and Conclusions sections of the Abstract. Note, the results are correctly presented in fig 1. These corrections do not affect the authors’ interpretation of results or stated conclusions.