Goonj

Goonj (गूँज — Hindi/Urdu for "echo, resonance") — acoustics engine for the AGNOS ecosystem.

Built on hisab for math. Provides sound propagation, room simulation, impulse response generation, acoustic ray tracing, diffraction, and resonance analysis.

Features

• Propagation — speed of sound, inverse square law, atmospheric absorption, Doppler shift
• Room geometry — walls, shoebox constructor, surface area, volume
• Materials — frequency-dependent absorption (7 presets: concrete, carpet, glass, wood, curtain, drywall, tile)
• Impulse response — Sabine RT60, Eyring RT60, energy decay curve
• Ray tracing — acoustic ray intersection, specular reflection with energy absorption
• Diffraction — occlusion detection, edge diffraction loss (UTD simplified)
• Resonance — room modes, axial modes, Schroeder frequency, modal density

Quick Start

use goonj::{propagation, impulse, material::AcousticMaterial, room::AcousticRoom};

// Speed of sound at 20°C
let speed = propagation::speed_of_sound(20.0);
assert!((speed - 343.4).abs() < 0.1);

// Create a shoebox room
let room = AcousticRoom::shoebox(10.0, 8.0, 3.0, AcousticMaterial::concrete());

// Compute reverberation time
let absorption = room.geometry.total_absorption();
let volume = room.geometry.volume_shoebox();
let rt60 = impulse::sabine_rt60(volume, absorption);
println!("RT60: {rt60:.2}s");

Dependency Stack

goonj (acoustics)
  └── hisab (math)

Consumers

• dhvani — impulse responses for convolution reverb
• shruti — room simulation for mixing
• kiran/joshua — game audio propagation, occlusion, spatial audio
• aethersafha — spatial audio for video conferencing

License

GPL-3.0-only