{
  "url": "https://openlegislation.uk/air-navigation-environmental-standards-for-non-part-21-aircraft-order-2008/schedule/part-2/paragraph-3",
  "json_url": "https://openlegislation.uk/air-navigation-environmental-standards-for-non-part-21-aircraft-order-2008/schedule/part-2/paragraph-3.json",
  "legislation": "uksi/2008/3133",
  "legislation_title": "The Air Navigation (Environmental Standards For Non-Part 21 Aircraft) Order 2008",
  "legislation_url": "https://openlegislation.uk/air-navigation-environmental-standards-for-non-part-21-aircraft-order-2008",
  "path": "schedule/part/2/paragraph/3",
  "kind": "paragraph",
  "number": "3",
  "heading": "Calculation of sound exposure level LAE from measured noise data",
  "text": "(1) The sound exposure level LAE is defined as the level, in decibels, of the time integral of squared ‘A’-weighted sound pressure (PA) over a given time period or event, with reference to the square of the standard reference sound pressure (Po) of 20 micropascals (P) and a reference duration of one second.\n(2) This unit is defined by the expression—\nwhere To is the reference integration time of one second and (t2 - t1) is the integration time interval.\n(3) The above integral can also be expressed as—\nwhere LA(t) is the time varying ‘A’-weighted sound level.\n(4) The integration time (t2 - t1) in practice must not be less than the time interval during which LA(t) first rises to within 10dB(A) of its maximum value (LAmax) and last falls below a level of 10dB(A) less than its maximum value.\n(5) The LAE may be approximated by the following expression for LAmax—\nLAE=LAmax+ΔAwhere ΔA is the duration allowance given by ΔA = 10 log τ where τ = (t2-t1)/2.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/uksi/2008/3133/schedule/part/2/paragraph/3",
    "retrieved_at": "2026-10-29T03:20:36.505205+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}