# PathRIR: Physics-Guided Acoustic Path Selection and Late-Tail Compensation for Fast Room Impulse Response Simulation

arXiv: https://arxiv.org/abs/2607.23293 · HTML: https://mlsanity.com/paper/2607.23293/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 15 of its 30 references that are in the map.
- First posted on arXiv 25 Jul 2026.

## Builds on (most cited first, 15 of 15)

- [Pyroomacoustics: A Python package for audio room simulations and array processing algorithms](https://mlsanity.com/paper/1710.04196/) (2017)
- [SoundSpaces 2.0: A Simulation Platform for Visual-Acoustic Learning](https://mlsanity.com/paper/2206.08312/) (2022)
- [gpuRIR: A Python Library for Room Impulse Response Simulation with GPU Acceleration](https://mlsanity.com/paper/1810.11359/) (2018)
- [FAST-RIR: Fast neural diffuse room impulse response generator](https://mlsanity.com/paper/2110.04057/) (2021)
- [MESH2IR: Neural Acoustic Impulse Response Generator for Complex 3D Scenes](https://mlsanity.com/paper/2205.09248/) (2022)
- [Neural Acoustic Context Field: Rendering Realistic Room Impulse Response With Neural Fields](https://mlsanity.com/paper/2309.15977/) (2023)
- [AV-RIR: Audio-Visual Room Impulse Response Estimation](https://mlsanity.com/paper/2312.00834/) (2023)
- [TS-RIR: Translated synthetic room impulse responses for speech augmentation](https://mlsanity.com/paper/2103.16804/) (2021)
- [Improving Reverberant Speech Training Using Diffuse Acoustic Simulation](https://mlsanity.com/paper/1907.03988/) (2019)
- [NeRAF: 3D Scene Infused Neural Radiance and Acoustic Fields](https://mlsanity.com/paper/2405.18213/) (2024)
- [FRA-RIR: Fast Random Approximation of the Image-source Method](https://mlsanity.com/paper/2208.04101/) (2022)
- [Acoustic Reflector Localization: Novel Image Source Reversion and Direct Localization Methods](https://mlsanity.com/paper/1610.05653/) (2016)
- [Room-acoustic simulations as an alternative to measurements for audio-algorithm evaluation](https://mlsanity.com/paper/2509.05175/) (2025)
- [Fast Random Approximation of Multi-channel Room Impulse Response](https://mlsanity.com/paper/2304.08052/) (2023)
- [RIR-Former: Coordinate-Guided Transformer for Continuous Reconstruction of Room Impulse Responses](https://mlsanity.com/paper/2602.01861/) (2026)

## Abstract (arXiv)

Image-source-method (ISM)-based room impulse response (RIR) simulation is a useful and physically interpretable tool for acoustic scene modeling, but full-order ISM becomes computationally expensive as the reflection order and room complexity increase. We propose a physics-guided framework for fast RIR simulation that preserves the geometric structure of ISM while learning to retain only acoustically important image-source paths during online traversal. To recover energy removed by pruning, the proposed PathRIR uses a lightweight compensation multilayer perceptron to predict the missing late-tail energy envelope and generate a compensation tail whose energy follows that envelope. Experiments on irregular 3D rooms show that PathRIR reduces image-source computation and improves runtime efficiency over a full-order ISM simulator, while achieving low waveform- and decay-related errors. Ablation results show that adding the compensation tail improves waveform fidelity and reduces energy-decay-curve error, reverberation-time error, and direct-to-reverberant-ratio error, with modest runtime overhead.