ATAcoustic Toolbox

Propagation

Outdoor Sound Propagation

Move the source, receiver and noise barriers to explore frequency-dependent outdoor sound propagation.

Source, receiver, ground and barrier geometryDrag the source, receiver and barrier tops. The direct and diffracted propagation paths update immediately.SOURCERECEIVER

Drag source, receiver or barrier top. The axes expand automatically beyond the default 100 × 20 m range.

Geometry & environment

Third-octave spectrum at receiver

Hover or focus a band for its attenuation breakdown.

Source LWReceiver Lp

Select a band to inspect its attenuation components.

BandSource LWAdivAatmAgrAbarReceiver Lp

Calculation scope

The model calculates geometrical divergence and atmospheric absorption by frequency. Atmospheric absorption follows ISO 9613-1:1993 using temperature, relative humidity and pressure. The propagation structure follows ISO 9613-2:2024, which predicts outdoor environmental noise under meteorological conditions favourable to propagation.

Ground and barriers

The current ground contribution is a deliberately bounded homogeneous-ground approximation controlled by G; it does not yet reproduce the complete source, middle and receiver region procedure of ISO 9613-2:2024. Barrier insertion loss uses the single-edge Maekawa approximation from path difference and Fresnel number. For multiple barriers, only the strongest individual screen is applied because independent screen losses must not simply be added.