A Survey of the Noise Attenuation Characteristics of Navy Air Traffic Control Towers

Abstract

The sound-pressure levels of a standardized noise source were measured in octave bands both inside and on the catwalk just outside the cab of fifteen control towers. A twin-engine Beechcraft, positioned 100 feet from the base of the tower was used as a standardized source. The attenuation for the towers averaged 20–27 db in the octave bands between 75–9600 cps. The attenuation for four modern navy towers, currently the standard navy structure, was about 5 db better in the octave bands primarily affecting speech 600–1200, 1200–2400, 2400–4800 cps. These values of attenuation were then used to rate these towers with regard to Speech Communication Criteria. The results indicate that the current navy structures are adequate for communication in the towers for airfields with piston-driven planes, but communication difficulties should be expected in the presence of jet planes. Tapes recorded in the control towers will be used to demonstrate the accuracy of these predictions.