Community Acceptance Of Helicopter Noise:

SUMMARY

A study was conducted to define those criteria necessary for civil helicopter operations to be acoustically acceptable to the communities from which they operate and over which they fly. The study involved surveying existing domestic and foreign Federal regulations and guidelines, state and local noise ordinances, results of community noise annoyance studies, and results of individual aircraft noise annoyance studies in order to establish the criteria. The final criteria selected are based on the Day-Night Noise Level, %u, a measure of total noise exposure. weighted sound pressure level (dBA) which has accuracy comparable to other units currently used for aircraft. An Lterion for areas where the ambient noise is below 58 dBA. 2 dBA above the local ambient is recommended for areas where the ambient is above 58 dBA. source (such as aircraft operations) is less than the existing ambient noise energy. Characteristics found important for aircraft noise rating such as tone content, duration, and number of operations have been accounted for....