Two-Stage Multi-modal Learning for Dynamic Audio-Visual Navigation: From Physical Alignment to Scene Aggregation
Organizations: School of Computer Science and Technology, Xinjiang University, Urumqi 830017, China · Joint Research Laboratory for Embodied Intelligence, Xinjiang University · Joint International Research Laboratory of Silk Road Multilingual Cognitive Computing, Xinjiang University
Abstract
Embodied Audio-Visual Navigation (AVN) requires an agent to locate sound targets by jointly leveraging visual and auditory cues. While prior work has achieved notable success with static sound sources, real-world scenarios often involve moving targets, giving rise to the more challenging problem of Dynamic Audio-Visual Navigation (D-AVN). Existing approaches largely rely on semantic auditory features, which limits generalization to unheard sound categories and hinders fine-grained spatial reasoning. To address these challenges, we propose a novel Two-Stage Multi-modal Learning framework for D-AVN. In the Physical Alignment stage, the proposed Intensity-Calibrated Geometry Encoder (ICGE) performs physics-informed alignment of sound intensity with visual geometry to capture category-agnostic spatial correspondence. In the Scene Aggregation stage, a Transformer-based Cross-Modal Scene Aggregator (CMSA) dynamically integrates multi-modal features to construct a robust state representation for policy learning. Extensive experiments on Replica and Matterport3D demonstrate that our method achieves state-of-the-art success rates, while significantly improving generalization and navigation efficiency in complex environments and under unheard sound scenarios.
Figures & tables
| Encoder | Kernel, Stride |
|---|---|
| CNN 1 | (8, 4), (4, 2), (3, 1) |
| CNN 2 | (8, 4), (4, 2), (3, 2), (2, 1) |
| CNN 3 | (8, 4), (4, 2), (3, 2), (3, 2) |
| CNN 4 | (8, 4), (4, 2), (3, 2), (2, 1) |
| Hyperparameter | Value |
|---|---|
| Optimizer | Adam |
| PPO clip | 0.1 |
| PPO epochs | 4 |
| Mini-batches | 1 |
| Value loss coefficient | 0.5 |
| Entropy coefficient | 0.02 |
| Model | Replica | Matterport3D | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Heard | Unheard | Heard | Unheard | |||||||||
| DSR | DSPL | DSNA | DSR | DSPL | DSNA | DSR | DSPL | DSNA | DSR | DSPL | DSNA | |
| AV-Nav | 71.0 | 47.2 | 16.3 | 37.4 | 23.4 | 7.8 | 73.0 | 43.4 | 18.4 | 35.5 | 20.9 | 8.4 |
| AV-WaN | 86.8 | 55.0 | 32.6 | 38.2 | 24.1 | 14.2 | 86.7 | 58.3 | 33.6 | 47.2 | 30.0 | 17.4 |
| SAVi | 67.6 | 54.0 | 25.7 | 40.8 | 28.9 | 13.9 | 49.0 | 29.9 | 11.3 | 41.6 | 26.3 | 10.0 |
| FSAAVN | 80.1 | 52.5 | 28.8 | 39.2 | 28.9 | 15.8 | 83.9 | 47.8 | 24.4 | 43.3 | 27.6 | 18.7 |
| Model | Replica | Matterport3D | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Heard | Unheard | Heard | Unheard | |||||||||
| DSR | DSPL | DSNA | DSR | DSPL | DSNA | DSR | DSPL | DSNA | DSR | DSPL | DSNA | |
| AV-Nav | 60.4 | 34.0 | 11.5 | 45.4 | 26.0 | 8.7 | 63.2 | 34.4 | 13.4 | 46.2 | 24.6 | 9.3 |
| AV-WaN | 66.3 | 43.1 | 25.1 | 51.5 | 32.8 | 19.0 | 84.0 | 52.3 | 31.5 | 70.3 | 43.0 | 25.6 |
| SAVi | 45.5 | 34.2 | 16.1 | 38.3 | 27.7 | 12.7 | 65.6 | 44.0 | 22.0 | 55.5 | 35.1 | 16.0 |
| FSAAVN | 63.1 | 37.5 | 18.8 | 49.9 | 29.9 | 17.6 | 70.9 | 39.5 | 19.2 | 62.8 | 30.7 | 20.4 |
| Model | Heard | Unheard | ||||
|---|---|---|---|---|---|---|
| DSR | DSPL | DSNA | DSR | DSPL | DSNA | |
| Replica | ||||||
| CMHM | 67.6 | 43.9 | 24.5 | 67.3 | 33.9 | 19.1 |
| Ours | 79.2 | 55.6 | 32.6 | 64.0 | 37.6 | 22.3 |
| Matterport3D | ||||||
| CMHM | 91.9 | 61.6 | 36.2 | 74.0 | 45.8 | 26.0 |
| Model | Heard | Unheard | ||||
|---|---|---|---|---|---|---|
| SR | SPL | SNA | SR | SPL | SNA | |
| CMHM | 82.9 | 61.9 | 46.8 | 55.3 | 42.4 | 31.6 |
| AGSA-AVN | 70.0 | 54.1 | 30.0 | 36.5 | 26.2 | 13.1 |
| IRCAM-AVN | – | – | – | 61.5 | 37.8 | 52.4 |
| DMTF-AVN | – | – | – | 63.1 | 38.4 | 54.2 |
| Ours | 84.3 | 64.9 | 48.5 | 62.6 | 48.4 | 35.0 |
| Model Variant | Heard | Unheard | Efficiency | ||||||
|---|---|---|---|---|---|---|---|---|---|
| DSR | DSPL | DSNA | DSR | DSPL | DSNA | Params (M) | Train FPS | Latency (ms) | |
| Baseline1 ( ) | 90.0 | 62.6 | 34.5 | 49.1 | 29.4 | 16.1 | 13.48 | 35.87 | 3.19 |
| Baseline2 ( ) | 89.3 | 63.2 | 35.5 | 49.3 | 28.7 | 16.0 | 6.16 | 34.68 | 3.15 |
| w/ ICGE | 91.2 | 66.4 | 36.5 | 54.2 | 30.6 | 17.2 | 6.62 | 33.65 | 4.43 |
| w/ CMSA | 91.5 | 64.2 | 36.0 | 51.8 | 31.1 | 17.8 | 3.63 | 33.83 | 4.39 |
| Full Model (Ours) | 93.8 | 67.5 | 37.5 | 63.5 | 32.1 | 17.8 | 3.90 | 32.22 | 5.84 |
| Model Variant | Heard | ||
|---|---|---|---|
| DSR | DSPL | DSNA | |
| Baseline | 90.0 | 62.6 | 34.5 |
| Variant-L1 | 87.6 | 62.7 | 36.3 |
| Variant-L2 | 90.8 | 63.0 | 36.9 |
| Variant-L3 | 91.6 | 65.1 | 35.8 |
| Full Model (Ours) | 93.8 | 67.5 | 37.5 |