Examination of the low frequency limit for helicopter noise data in the Federal Aviation Administration's Aviation Environmental Design Tool and Integrated Noise Model

The Federal Aviation Administration (FAA) aircraft noise modeling tools Aviation Environmental Design Tool (AEDTc) and Integrated Noise Model (INM) do not currently consider noise below 50 Hz in their computations. This paper describes a preliminary study to determine the effect of including low-frequency data on the accuracy of AEDT/INM results. Expanded aircraft noise spectra containing one-third octave band data to 12.5 Hz were analyzed using methods adapted from AEDT/INM. Results from expanded spectral data are compared with results from the historical AEDT/INM spectral data (one-third octave band data from 50 Hz to 10 kHz). This comparison showed a range of differences, from increases in overall unweighted sound pressure levels (SPL), to negligible changes in A-weighted and Time Audible metrics. These changes may be particularly important for helicopters, with dominant low-frequency rotor noise below 50 Hz. Following the comparison, the potential implementation of expanded spectral data in AEDT is discussed.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 12p

Subject/Index Terms

Filing Info

  • Accession Number: 01518854
  • Record Type: Publication
  • Created Date: Mar 13 2014 3:47PM