Retrieving to Recover: Towards Incomplete Audio-Visual Question Answering via Semantic-consistent Purification
Authors: Jiayu Zhang, Shuo Ye, Qilang Ye, Zihan Song, Jiajian Huang, Zitong Yu
Organizations: School of Computing and Information Technology, Great Bay University · Tsinghua Shenzhen International Graduate School, Tsinghua University · College of Computer Science, Nankai University · School of mathematics, Sun Yat-sen University · Dongguan Key Laboratory for Intelligence and Information Technology
Recent Audio-Visual Question Answering (AVQA) methods have advanced significantly. However, most AVQA methods lack effective mechanisms for handling missing modalities, suffering from severe performance degradation in real-world scenarios with data interruptions. Furthermore, prevailing methods for handling missing modalities predominantly rely on generative imputation to synthesize missing features. While partially effective, these methods tend to capture inter-modal commonalities but struggle to acquire unique, modality-specific knowledge within the missing data, leading to hallucinations and compromised reasoning accuracy. To tackle these challenges, we propose R2ScP, a novel framework that shifts the paradigm of missing modality handling from traditional generative imputation to retrieval-based recovery. Specifically, we leverage cross-modal retrieval via unified semantic embeddings to acquire missing domain-specific knowledge. To maximize semantic restoration, we introduce a context-aware adaptive purification mechanism that eliminates latent semantic noise within the retrieved data. Additionally, we employ a two-stage training strategy to explicitly model the semantic relationships between knowledge from different sources. Extensive experiments demonstrate that R2ScP significantly improves AVQA and enhances robustness in modal-incomplete scenarios.
Figures & tables
Figure 1: Comparison of traditional methods (top) and R 2 ScP (bottom). Traditional methods typically rely on modality imputation but often yield redundant common knowledge that lacks distinctiveness. In contrast, R 2 ScP preserves valuable modality-specific knowledge from the candidate pool while effectively suppressing the inherent noise knowledge.
Figure 2: Overview of the proposed R 2 ScP framework (when the audio modality is missing). (a) The CMR module retrieves candidate features from a unified semantic space, while the CAP mechanism acts as a semantic filter that refines the coarse retrieved features using the common knowledge between the visual and audio modalities. (b) The overall architecture processes available and purified representations for the answer decoder.
Figure 3: Two-stage training strategy sequentially performs expert pre-training and expert mixing optimization.
Method
Venue
Modalities
Music-AVQA (Audio-Visual)
AVQA
A
V
Q
Exist
Localis
Count
Comp
Temp
Avg.
Avg.
AVQA Specialized Models
PSTP-Net
MM’23
∙
∙
∙
76.18
73.23
71.80
71.79
69.00
72.57
90.20
TSPM
MM’24
∙
∙
∙
82.19
71.85
76.21
65.76
71.17
73.51
90.80
SHMamba
TASLP’25
∙
∙
∙
82.89
67.93
72.65
61.31
68.37
70.64
90.80
QA-TIGER
CVPR’25
∙
∙
∙
83.10
72.50
78.58
63.94
69.59
73.74
–
Table 1: Comparison of different methods on Music-AVQA and AVQA dataset under various missing modality settings ( ∘ indicates a missing modality). A: audio, V: visual, Q: question. Exist, Localis, etc. represent the accuracy in the subtasks of the Music-AVQA dataset.
Modalities
Modules
MUSIC AVQA
AVQA
A
V
CMR
CAP
∙
∘
62.43
57.43
∙
∘
✓
64.11
59.64
∙
∘
✓
67.21
61.78
∙
∘
✓
✓
69.37
63.25
∘
∙
63.54
68.02
Table 2: Ablation on the different components of R 2 ScP.
Figure 4: Impact of purification budget k and number of retrieved samples n .
Method
Avg.
R 2 ScP (ours)
70.72
w/o modality-specific expert pretraining
68.98
w/o expert mixing training
64.21
w/o ranking loss
69.62
Table 3: Effectiveness of the two-stage training strategy. Results are the average performance on Music-AVQA for the visual and audio missing settings.
Figure 5: Generalization analysis on the Music-AVQA dataset across various missing rates
Corpus
Music-AVQA
AVQA
N/A
64.66
64.39
AVQA
66.51
69.19
VGGSound
66.92
69.64
Music-AVQA
70.72
65.72
Table 4: Impact of different retrieval corpora on the performance of Music-AVQA and AVQA datasets. Results are the average performance for the visual and audio missing settings.
Figure 6: Trends in expert loads during experts mixing training on Music-AVQA in the severely incomplete conditions.
Figure 7: t-SNE visualization of our model and other methods on the Music-AVQA dataset.
Tianjin Key Laboratory of Cognitive Computing and Application, Tianjin University, Tianjin, China · Tencent, China · Huiyan Technology Company, Ltd., Tianjin, China +1