# Two acoustic tools online: acoustic map and noise-barrier calculator > ST-LINE Open Lab's two browser acoustic tools are live: acmap v0.5 for surveys and propagation and noise-barrier-calc v0.8 for insertion loss — open source. Published: 2026-05-19 Category: acustica Tag: iso-9613-2, maekawa, environmental-acoustics, open-lab, leaflet, browser-tools Page: --- > **Status note (updated 25 August 2026).** This article describes the May 2026 versions: > acmap v0.5 and noise-barrier-calc v0.8. The shared engine has changed substantially since — > ISO 9613-2:2024 screening became the default, §7.4.3 lateral diffraction was added, and the > composition of ground effect and screening, the K_met distances, power conservation in source > discretisation and spectrum normalisation were all corrected. For the current state see the > [acmap](/en/wiki/acmap/) and [noise-barrier-calc](/en/wiki/noise-barrier-calc/) wikis and the > live tools. Live in the [Open Lab](/en/open-lab/) section are the two browser-based acoustic tools ST-LINE maintains as a working lab for our own environmental-acoustics algorithms. Open source on GitHub, fully client-side (no backend, no data upload), sharing the same ISO 9613-2 §7.4 physics engine with selectable Maekawa diffraction. ## acmap — acoustic map (v0.5) [acmap](https://github.com/stefanofante/acmap) — [live tool](/en/tools/acoustic-map/) · [wiki](/en/wiki/acmap/) Visualises a sound-level survey loaded as CSV (lat, lon, Leq) and simulates point-source propagation with Maekawa diffraction on real buildings fetched from OpenStreetMap via Overpass API. Two complementary modes: **Measure** shows the loaded survey as a coloured heatmap with arithmetic statistics over the loaded points; **Predict** computes the sound level over a receiver grid with diffraction on the OSM buildings (worst-screen-wins, one obstacle per source–receiver pair). What's new in v0.5: an explainer block above the statistics that makes clear *what* is being computed — the "Mean Leq" is the arithmetic mean of the loaded survey, **not** an energy-averaged mean, and the block says so explicitly to avoid the common misreading. Per-stat technical sublabels and a fixed offset on the OSM building tooltip round out the iteration. ## noise-barrier-calc — noise barrier calculator (v0.8) [noise-barrier-calc](https://github.com/stefanofante/noise-barrier-calc) — [live tool](/en/tools/barrier-calculator/) · [wiki](/en/wiki/noise-barrier-calc/) Verifies the effectiveness of a noise barrier for a point, line, or area source over a configurable receiver grid. Computes the insertion loss (`IL = Leq_no_barrier − Leq_with_barrier`) in octave bands with selectable ISO 9613-2 §7.4 screening (with `K_met`) or Maekawa 1968 diffraction, and draws a banded map plus 5 dB isolines. v0.8 collects several months of work on robustness and UX: - **Adaptive receiver grid**: auto-fits the source's bounding box + a user-configurable buffer per side. v0.7 had a fixed 300×300 m grid that truncated extended line/area sources. - **Up to 5 manual receivers** at specific points (e.g. sensitive façades) with a dedicated results table, numbered draggable markers, and a CSV-export `manual` flag distinguishing grid points from pointwise ones. - **Result-explainer notes**, per-stat technical sublabels, and supplementary "diffracted only" statistics — more indicative of barrier effectiveness than the full-grid mean (which includes front-of-barrier zones with IL≈0). - **Auto-redraw** on view-mode change (Insertion Loss / Leq with barrier / Leq without) — no recompute needed. - **Defensive fallback** on an empty barrier-height field: previously produced `IL = ∞` in the statistics, now falls back to "no barrier" with a clear status warning. - **Compact panel layout** that eliminates the wasted vertical space between sections of differing height. ## Status, limits, and what they are NOT Both tools are **demonstrative**: useful for exploration, teaching, and preliminary assessments. They **do not replace a calculation model adequate to the required methodology** — CadnaA, SoundPLAN and NoiseModelling are common examples, but “certified software” is not a category the regulation provides for — and they do not replace the judgement of a registered competent acoustic technician. Barrier/building diffraction is modelled as the single dominant obstacle per source–receiver pair (worst-screen-wins, **not** rigorous ISO 9613-2 multi-screen). acmap roadmap: Overpass mirror fallback + embedded offline dataset. noise-barrier-calc roadmap: lateral diffraction, multi-barrier cascade, source spectra from real CSV. Apache-2.0 with patent grant. Code, issues, contributions on GitHub.