{
  "url": "https://openlegislation.uk/eu-directive-2015-996/annex/division-ASSESSMENT/division-2/division-2.7/division-2.7.24",
  "json_url": "https://openlegislation.uk/eu-directive-2015-996/annex/division-ASSESSMENT/division-2/division-2.7/division-2.7.24.json",
  "legislation": "eudr/2015/996",
  "legislation_title": "Commission Directive (EU) 2015/996 of 19 May 2015 establishing common noise assessment methods according to Directive 2002/49/EC of the European Parliament and of the Council (Text with EEA relevance)",
  "legislation_url": "https://openlegislation.uk/eu-directive-2015-996",
  "path": "annex/division/ASSESSMENT/division/2/division/2.7/division/2.7.24",
  "kind": "division",
  "number": "2.7.24",
  "heading": "Weighted equivalent sound levels",
  "text": "Time-weighted equivalent sound levels, which account for all significant aircraft sound energy received, shall be expressed in a generic manner by the formula\nL eq,W = 10 × lg t 0 T 0 × ∑ i = 1 N g i × 10 L E,i ∕ 10 + C\n(2.7.56)\nThe summation is performed over all N noise events during the time interval T 0 to which the noise index applies. LE,i is the single event noise exposure level of the i-th noise event. gi is a time-of-day dependent weighting factor (usually defined for day, evening and night periods). Effectively gi is a multiplier for the number of flights occurring during the specific periods. The constant C can have different meanings (normalising constant, seasonal adjustment etc.).\nUsing the relationship\ng i = 10 Δ i ∕ 10\nwhere Δi is the decibel weighting for the i-th period, equation (2.7.56) can be rewritten as\nL eq,W = 10 × lg t 0 T 0 ∑ i = 1 N 10 L E,i + Δ i ∕ 10 + C\n(2.7.57)\ni.e. the time-of-day weighting is expressed by an additive level offset.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eudr/2015/996/annex/division/ASSESSMENT/division/2/division/2.7/division/2.7.24",
    "retrieved_at": "2026-11-01T15:21:38.862218+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."
}