Text-to-spatial audio generation, such as text-to-First-Order Ambisonics (FOA), provides a convenient way to create spatial audio for billion-dollar gaming and film industries. However, existing text-to-FOA methods are largely data-driven and may produce audio that violates acoustic relations between source direction and distance. They also separate descriptive and parametric control, forcing users to trade usability for precision. In this paper, we present PhysWave, a physics-guided latent diffusion model for controllable text-to-FOA generation. PhysWave unifies natural-language and trajectory control through a shared waypoint-caption representation, and augments diffusion training with two differentiable acoustic priors: spherical-harmonic direction consistency and inverse-square distance consistency. To support dynamic spatial generation, we further construct a 300K-clip FOA dataset with diverse sound categories and source trajectories. Extensive results show that the proposed priors help PhysWave generate spatially consistent FOA audio while maintaining competitive audio quality. Further analyses show that these physics priors improve spatial consistency during training and can also be used as inference-time guidance for training-free spatial refinement.
Figures & tables
Figure 1: Dataset construction pipeline. Captioned monaural audio is paired with sampled trajectories and rendered into FOA audio through simulation.
Figure 2: Overview of PhysWave. A spatial caption is parsed into an acoustic caption and a waypoint trajectory. Text, waypoint, and temporal tokens jointly condition an FOA latent diffusion model, which is trained with latent denoising loss and physics-consistency losses on the decoded FOA waveform.
Variant
Audio quality
Spatial fidelity
FD ↓
FAD CLAP ↓
CLAP ↑
KL ↓
IS ↑
Static ( ∘ ) ↓
Moving ( ∘ ) ↓
InvSq Err. (dB) ↓
InvSq Corr. ↑
Trajectory text
23.13
0.20
0.32
1.74
8.05
7.33
17.62
4.59
0.62
PhysWave (w/o physics)
21.92
0.20
0.33
1.69
8.22
2.05
6.50
5.15
0.48
PhysWave (w/o Ldist )
21.79
0.20
0.33
1.68
8.15
1.75
4.81
4.79
0.59
PhysWave (w/o Ldir )
21.34
0.20
0.33
1.67
8.25
2.47
6.60
3.78
0.74
PhysWave
21.22
0.21
0.33
1.66
8.31
1.73
4.65
4.06
0.73
Table 1: Ablation study of PhysWave. All variants use the same generative backbone and caption condition. Angular errors are reported in degrees, and InvSq Err. is reported in dB.
Model
Control
Static ( ∘ ) ↓
Moving ( ∘ ) ↓
ID-D
Static text
7.07
–
ID-P
Static param.
2.79
–
SM-D
Circular text
20.82
31.09
SM-P
Circular param.
2.41
19.22
PhysWave
Text + Waypoints
1.73
5.78
Table 2: Reference comparison with published results from prior FOA generation methods. ID and SM denote ImmerseDiffusion and SonicMotion, respectively. D and P denote descriptive and parametric conditioning.
Figure 3: Qualitative trajectory comparison between PhysWave with and without physics-consistency losses.
Model
FD ↓
FAD CLAP ↓
CLAP ↑
KL ↓
IS ↑
AudioLDM
31.67
0.33
0.33
2.37
6.96
AudioLDM 2
24.13
0.12
0.33
2.11
8.62
Make-An-Audio
15.44
0.11
0.37
1.93
8.79
Make-An-Audio 2
13.86
0.14
0.40
1.73
10.85
Stable Audio Open
30.84
0.31
0.30
2.30
11.09
ImmerseDiffusion
20.45
0.14
0.35
1.66
9.55
Table 3: Audio quality comparison on the omnidirectional W channel.
Parser
Spatial Faith. ↑
Semantic Pres. ↑
Qwen3.5-0.8B
1.89 ± 0.20
3.40 ± 0.38
Llama-3.2-3B-Instruct
2.40 ± 0.24
4.18 ± 0.29
Qwen3.5-4B
3.88 ± 0.28
4.72 ± 0.17
Table 4: LLM parser evaluation on spatial captions. Scores are reported as mean ± standard deviation.
Source
MOS-
MOS-
MOS-
Event ↑
Trajectory ↑
Realism ↑
Real FOA Recording
4.89
4.56
4.79
AudioLDM2
2.70
2.07
2.07
Stable Audio Open
3.40
2.21
2.51
PhysWave
4.32
3.90
3.48
Table 5: Subjective evaluation of generated FOA audio. MOS scores are obtained from 14 participants.
Figure 4: Effect of inference-time physics guidance.
Method
Format
Conditioning
Spatial Source
Trajectory Control
Physics-Guided
Static
Moving
AudioLDM ( Liu et al., 2023 )
Mono
Text
–
–
–
✗
AudioLDM 2 ( Liu et al., 2024 )
Mono
Text
–
–
–
✗
Make-An-Audio ( Huang et al., 2023b )
Mono
Text
–
–
–
✗
Make-An-Audio 2 ( Huang et al., 2023a )
Mono
Text
–
–
–
✗
TANGO ( Ghosal et al., 2023 )
Mono
Text
–
–
–
✗
Table 6: Functional comparison with prior audio generation methods. Mono, Stereo, Binaural, and FOA denote output formats. ✓ means supported, ✗ means not supported, and “–” means not applicable. For SpatialSonic, trajectory control refers to azimuth-level control, while PhysWave supports listener-relative waypoint trajectories with azimuth, elevation, and distance. Physics-guided means that explicit acoustic priors are used during generation.
Family
Ratio
Sampling Range
Description
Static
50.0%
θ∈[−180∘,180∘] , ϕ∈[−35∘,35∘] , r∈[0.5,5] m
Fixed direction and distance
Linear pass-by
≈16.7%
v∈[1,25] m/s, dmin∈[1,8] m
Coupled direction and distance changes
Circular
≈16.7%
r∈[0.5,5] m, angular span ≥30∘
Direction changes at near-constant distance
Approach/recede
≈16.7%
v∈[2,6] m/s, r∈[1,60] m
Distance changes with fixed direction
Table 7: Trajectory sampling configuration. Each retained monaural clip is rendered once as a static source and once as a moving source.
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
Data Source
Train
Test
Clips
Duration (h)
Clips
Duration (h)
AudioCaps
46,696
129.7
4,239
11.8
WavCaps
107,850
299.6
–
–
Clotho
2,863
8.0
1,021
2.8
Total monaural
157,409
437.2
5,260
14.6
Rendered FOA
314,818
874.5
10,520
29.2
Appendix
Table 8: Statistics of source data after preprocessing. Each retained monaural clip is rendered twice, once as a static source and once as a moving source.
Figure 5: Prompt used by the LLM spatial parser. The parser outputs a compact trajectory representation, which is converted into the M=10 waypoint condition used by the diffusion model.
Figure 6: Example outputs of the LLM spatial parser. Each output keeps the non-spatial acoustic content and converts the spatial description into a parametric trajectory.
Figure 7: Prompt used for LLM-as-a-judge parser evaluation. The judge compares the original spatial caption with the parsed acoustic caption and converted waypoints.
Model
STFT ↓
Mel ↓
L1 (θ)↓
L1 (ϕ)↓
Δangle↓
FOA VAE
1.44
1.11
0.87 ∘
1.45 ∘
1.92 ∘
Appendix
Table 9: FOA VAE reconstruction quality.
Figure 8: More qualitative trajectory comparison between PhysWave with and without physics-consistency losses.
Figure 9: Energy envelope comparison. PhysWave better follows the target inverse-square log-energy profile, while the model without physics losses shows larger temporal deviations.
The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA · Advanced Technology Group, Dolby Laboratories, San Francisco, CA, USA