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

2026-07-25

AI Summary

This work addresses the high computational cost of traditional image source method (ISM) in simulating room impulse responses (RIRs), particularly in complex or high-order reflective environments. The authors propose a physics-guided, efficient RIR simulation framework that preserves geometric structure during online traversal while selectively tracing only acoustically significant image paths. To compensate for truncated late reflections, a lightweight multilayer perceptron is introduced to predict the late reverberant energy envelope and synthesize a residual tail. By integrating physical priors with data-driven modeling, the method achieves effective path pruning and energy compensation. Experimental results demonstrate that, in irregular 3D rooms, the approach substantially reduces computational overhead and runtime while maintaining low waveform and decay errors, thereby improving the accuracy of modeled reverberation time, decay curves, and direct-to-reverberant ratio.

Abstract

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.

Problem

• Room Impulse Response
• Image Source Method
• Computational Efficiency
• Acoustic Simulation
• Late Reverberation

Innovation

• Physics-guided
• Image-source method
• Late-tail compensation
• Fast RIR simulation
• Acoustic path selection