The following departure noise events were recorded using a CEL593 Sound Level Meter and a Sony TCD D10 Pro II DAT recorder, at a site 4.88 kilometres from start of take-off roll to the east of London Heathrow Airport..

All the recordings provided here were taken at the same location on the same day. The DAT recordings have been converted to MP3 format files whilst retaining the relative sound level differences of the original recordings.

In order to prevent clipping of the sound files the maximum sound level was set by the loudest sound (Concorde). The smaller more modern aircraft sound very quiet. The sound files do, however, reflect the difference in sound levels between older Chapter 2 and more modern Chapter 3 aircraft.