# Composizione livelli sonori

> Logarithmic sum of several sound levels and background-noise correction, with the ISO 1996-2 thresholds (UNI 9884 is withdrawn).

Practice: acustica
Field: edilizia
Status: Tool
Tag: ISO 1996-2, dB sum
Method, assumptions and limits: <https://www.stline.it/en/wiki/composizione-livelli/index.md>

Page: <https://www.stline.it/en/tools/level-composition/>

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Demonstrative tool for composing sound levels. Dynamic list of sources (level in dB, A/C/Z weighting, optional label); energetic sum L = 10·log₁₀(Σ 10^(Lᵢ/10)) with a contributions table and bar chart. Optional background-noise subtraction section with the ISO 1996-2 thresholds (ΔL > 10 dB negligible, 3–10 dB corrected, < 3 dB unreliable: the value shown is an upper bound).

This file is a **descriptor**, not the tool's documentation: it says what the tool computes and by what method, in summary. Formulas, assumptions, validity conditions and limits are in the wiki linked above. The tool runs in the browser at the page given.