● ISO 9613-2 (1996 / 2024) engine

See the noise before you build the wall.

Site Acoustics turns an equipment layout into a clear, A-weighted noise map and per-receiver sound levels in seconds — on a propagation engine validated against the official ISO reference cases to ≤ 0.04 dB.

Site Acoustics noise map with source, barrier shadow and receiver level
What it does

Model a site. Screen it. Read every receiver.

Load a site export or build from scratch, give each piece of equipment a sound-power spectrum, place the screening — and compute the field, the per-receiver levels, and each group's contribution.

📐

Standards-grounded

A per-octave ISO 9613-2 engine, validated against the official ISO/TR 17534-3 reference cases to ≤ 0.04 dB on the A-weighted total.

Built for iteration

Draw sources, walls, buildings, berms and receivers on a site plan; change a setting and recompute the whole field in seconds across all your CPU cores.

🔒

One file, nothing in the cloud

A project bundles geometry, spectra, settings, the site-plan picture and terrain into one portable file. Your data never leaves your machine.

Features

Everything a layout study needs

🗺️

Live noise map

Colour A-weighted field with contours, legend and units, drawn over your own site-plan image.

🎯

Per-receiver levels

Total level and per-group breakdown at each receiver, labelled on the map in dB or dB(A).

✏️

Draw & edit on the plan

Point, line and area sources; walls, buildings, berms, foliage, tanks and receivers — drag, reshape, edit.

🧱

Barrier material library

Pick a wall type and it applies the octave reflection, acoustic kind and a matched build cost in one click.

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Inspect sound paths

Right-click a receiver to draw every source path, colour-coded clear / screened / at-cap.

📊

Measured vs predicted

Record measurements or import a logger CSV, see the residual on the map, calibrate to fit in one step.

📋

BS 4142 assessment

Rating-level with character corrections, an Annex C tonal screen and the excess-over-background band.

⚙️

Calculation profiles

One-click Strict ISO 9613-2:2024 or CCi-Recommended enhancements; every option also a single toggle.

🖼️

Clean exports

PNG / PDF / SVG maps and detailed CSV results, including a per-source, per-octave breakdown.

Standards & compliance

Built on the standard, band by band

Site Acoustics implements ISO 9613-2 on a per-octave basis (63 Hz – 8 kHz), then A-weights and energy-sums to the overall level — following both the 1996 method and the 2024 revision where they differ.

ISO 9613-2 propagation paths from source to receiver ISO 9613-2 validated to 0.04 dB
ISO 9613-2:1996 / 2024Core outdoor propagation: geometric divergence, ground effect, barrier screening, directivity, foliage and meteorological correction.
ISO 9613-1Atmospheric absorption coefficients, driven by the temperature and humidity set in Meteorology.
ISO/TR 17534-3:2015The official software-validation test cases used to verify the engine.
BS 4142:2014+A1:2019Industrial/commercial rating-level assessment, including the Annex C tonal-prominence screen.
Supporting referencesDirectivity cross-checked against CadnaA conventions (VDI 3733 / ÖAL 28); methodology compared against CNOSSOS-EU.
How compliance is assured

Independently cross-checked at every layer

The engine is checked against an independent reference implementation and two established commercial solvers, with the results frozen as automated regression gates that run on every change.

Validation pipeline: ISO/TR 17534-3, CadnaA, dBmap, barrier classifier
✓ Primary proof

ISO/TR 17534-3

Official cases T01–T19 with certified per-band and total levels, tolerance ±0.05 dB, scored against an independent reference engine.

≤ 0.04 dB achieved
✓ Cross-check

CadnaA

DataKustik solver as oracle — barrier Abar, directivity Dc, line/area discretization and meteorological correction, isolated one mechanism at a time.

✓ Cross-check

dBmap

Whole-site receiver levels and around-corner lateral paths compared on live engineering jobs, locked as regression gates.

✓ Edge cases

Barrier classifier

Probst / Parzych synthetic cases gate grazing-floor, bright-zone and sub-wavelength screening behaviour.

Transparent by design. Every results export stamps the exact settings and calculation profile used, so a number can always be traced back to how it was produced. Formal compliance reporting should still account for site-specific meteorology and the conventions of the receiving authority.
Under the hood

What makes the engine different

The distinctive parts, described at a conceptual level — the exact formulations and implementation are proprietary.

1

True per-octave engine

Every interaction is evaluated band by band, so frequency-dependent ground, air absorption and screening fall out of the physics rather than a broadband approximation.

2

Over-top and around-the-ends screening

Barrier diffraction includes the paths bending around a wall's free ends — and optionally around building corners — so broadside receivers read correctly instead of several dB low.

3

Fresnel-gated reflections

Reflections appear only where a real specular bounce lands on a surface, weighted by how acoustically large that surface is — so short walls fade out instead of over-contributing.

4

Two propagation regimes

A strict standards-traceable mode, plus a downwind-transition mode for open, grazing and far-field layouts. The active profile is recorded on every export.

5

Distance-aware barrier floor

An explicit, validated relaxation lets just-breaking-the-sight-line screening decay with distance and frequency, matching modern reference behaviour.

6

Barrier material library

One choice sets the full octave reflection spectrum, the acoustic kind and a matched build cost — keeping acoustics and cost consistent with the design decision.

7

One-step calibration

Because propagation is linear in decibels, a source group's sound power is back-calculated directly from a measured level — exact, not iterative.

8

Fast, parallel compute

The whole-area map is computed across all CPU cores, so trying another layout is a few-second round trip, with a live progress indicator.

Get started

Map your next site in an afternoon.

A validated ISO 9613-2 engine, a drawing canvas, and exports your client will understand — running offline on your machine.