Traditional multimodal methods often assume static modality quality, which limits their adaptability in dynamic real-world scenarios. Thus, dynamical multimodal methods are proposed to assess modality quality and adjust their contribution accordingly. However, they typically rely on empirical metrics, failing to measure the modality quality when noise levels are extremely low or high. Moreover, existing methods usually assume that the initial contribution of each modality is the same, neglecting the intrinsic modality dependency bias. As a result, the modality hard to learn would be doubly penalized, and the performance of dynamical fusion could be inferior to that of static fusion. To address these challenges, we propose the Unbiased Dynamic Multimodal Learning (UDML) framework. Specifically, we introduce a noise-aware uncertainty estimator that adds controlled noise to the modality data and predicts its intensity from the modality feature. This forces the model to learn a clear correspondence between feature corruption and noise level, allowing accurate uncertainty measure across both low- and high-noise conditions. Furthermore, we quantify the inherent modality reliance bias within multimodal networks via modality dropout and incorporate it into the weighting mechanism. This eliminates the dual suppression effect on the hard-to-learn modality. Extensive experiments across diverse multimodal benchmark tasks validate the effectiveness, versatility, and generalizability of the proposed UDML. The code is available at https://github.com/shicaiwei123/UDML.
Figures & tables
Figure 1: Visualization of dynamic multimodal methods for audio-visual classification on the CREMA-D dataset. (a) Visual weighting coefficients obtained using different uncertainty estimation methods, such as energy score (ES) [ 47 ] and probabilistic embedding (PE) [ 8 ] , and the proposed UDML, as varying levels of noise ( σ ) are injected into the visual modality. (b) Performance Comparison of different methods under static and dynamic weighting when noise ( σ=5 ) is injected into the visual modality.
Figure 2: The framework of the unbiased dynamic multimodal fusion. It consists of two parts: 1) noise-aware uncertainty estimator, which measures the modality quality; 2) modality-dependency calculator, which quantifies the model’s dependency on each modality.
Methods
MVSA-Single
CREMA-D
Kinetics-Sounds
Acc
F1
Acc
F1
Acc
F1
Late Fusion [ 26 ]
76.88
75.72
58.83
59.43
64.97
65.21
MMBT [ 49 ]
78.50
-
64.25
65.43
65.89
-
TMC [ 11 ]
76.06
74.55
65.43
66.10
66.12
66.51
ITIN [ 33 ]
75.19
74.97
-
-
-
-
MVCN [ 41 ]
76.06
74.55
-
-
-
-
Table 1: Performance comparison of different methods on multimodal classification tasks on MVSA-Single, CREMA-D, and Kinetics-Sounds datasets.
Methods
CMU-MOSI
CMU-MOSEI
Acc7
F1
Corr
Acc7
F1
Corr
MIB [ 51 ]
48.6
85.3
0.798
54.1
86.2
0.790
HMA [ 23 ]
45.3
85.6
0.782
52.8
85.4
0.787
MIM [ 10 ]
47.0
85.9
0.805
52.5
86.3
0.792
GCNet [ 4 ]
44.9
85.1
-
51.5
85.2
-
ConFEDE [ 44 ]
42.3
85.5
0.784
54.9
85.8
0.780
Table 2: Performance comparison of different methods for multimodal regression tasks on CMU-MOSI and CMU-MOSEI datasets.
Datasets
Methods
Clean
Salt
Gaussian
Acc@ ϵ =0
Acc@ ϵ =5
Acc@ ϵ =10
Acc@ ϵ =5
Acc@ ϵ =10
MVSA-Single
Late fusion [ 26 ]
76.88
67.88
55.43
63.46
55.16
MMBT [ 49 ]
78.50
74.07
51.26
71.99
55.35
TMC [ 11 ]
74.88
68.02
56.62
66.72
60.36
QMF [ 47 ]
78.07
73.90
60.41
73.85
61.28
EAU [ 8 ]
79.15
74.81
61.04
73.89
62.04
Table 3: Performance comparison of different methods when 50% of the modalities suffer from salt and Gaussian noise, respectively. The mean and variance of the noise are 0 and ϵ , respectively.
Dataset
MVSA
CREMA-D
Kinetics-Sounds
Settings
Acc
Acc
Acc
Full
77.87
67.53
66.36
- NUE
74.56
64.60
64.33
- MC
75.44
64.10
65.41
- POS
76.16
66.49
64.92
Table 4: Ablation of the UDML method when 50% of the modalities suffer from Gaussian noise ( ϵ=5 ). We report the result of complete UDML (Full), the UDML without noise-aware uncertainty estimator (-NUE), the UDML without Modality-dependency Calculator (-MC), and the UDML without Progressive Optimization Strategy(POS).
Datasets
MVSA
CREMA-D
Kinetics-Sounds
Structure
Acc
Acc
Acc
MMTM
78.86
51.86
56.70
MMTM †
85.68
56.88
62.72
mmFormer
79.69
59.69
64.72
mmFormer †
85.33
63.14
67.51
Table 5: Performance evaluation after integrating the UDML method into CNN-based and Transformer-based architectures. † indicates that the UDML is applied.
Figure 3: Visualization of dynamic multimodal fusion for audio-visual classification on the CREMA-D dataset as varying levels of noise ( σ ) are injected into the visual modality.
Dynamic multimodal learning aims to learn robust representations by adaptively modeling information discrepancies across modalities. However, existing methods still suffer from two limitations: (i) static cross-modal alignment strategies usually impose uniform constraints on all samples while overlooking sample-wise variations, potentially leading to unreasonable over-alignment; and (ii) confidence- or uncertainty-aware fusion methods often fail to adequately account for feature magnitude and confidence differences across modalities. For modality pairs with significant feature magnitude differences or small confidence gaps, it might be unreliable to strictly align fusion weights according to confidence. To address these issues, we propose an Alignment- and Calibration-driven Multimodal Learning framework (ACML). Specifically, ACML incorporates a dynamic cross-modal triplet alignment module, which enforces strong semantic consistency for high-confidence positive pairs while encouraging diverse representation learning between high- and low-confidence positive pairs according to their confidence gaps. Additionally, ACML introduces a difference-aware attention calibration strategy that adaptively adjusts attention regularization based on feature magnitude and confidence differences across modalities, thereby mitigating biases caused by unreasonable fusion constraints. Extensive experiments on multiple multimodal benchmark datasets demonstrate that ACML consistently achieves superior performance and robustness over recent state-of-the-art methods.
Jinghao Xu, Zhenhua Guo, Xiaofeng Zhu +1
School of Computer Science and Engineering, University of Electronic Science and Technology of China, Chengdu,China · Tianyijiaotong Technology Ltd.,China · School of Computer Science and Technology, Hainan University, Haikou, China
Multimodal learning robust to missing modalities is essential for real-world applications. Existing methods mainly focus on inter-modality missing, where entire modalities are absent, while overlooking intra-modality degradation, where modalities are present but severely corrupted. In practice, these two types of missing often coexist, making existing approaches ineffective. To address this limitation, we propose General Incomplete Multimodal Learning (GIML), a unified framework that simultaneously handles both inter-modality missing and intra-modality degradation through dynamic quality perception. Specifically, GIML models heterogeneous missing patterns as continuous modality information degradation, enabling degradation-aware adaptive fusion. To achieve reliable quality perception, we introduce a Noise-aware Quality Estimator that learns the mapping from corrupted features to noise intensity through controlled noise injection. Furthermore, we propose a Noise-Semantic Decoupled module that separates semantic information from noise interference. This improves robustness and generalization to unseen corruption patterns. Extensive experiments across datasets with diverse modality types demonstrate the effectiveness and generality of GIML. Code is available at: https://github.com/Yu-Five/GIML.
Xiangyu Meng, Shicai Wei
University of Electronic Science and Technology of China
Multimodal data fusion involves integrating and analyzing information from multiple modalities to uncover latent correlations and complementary patterns, thereby enhancing data processing and decision-making. While existing methods for structured multimodal inputs are typically designed around specific tasks and assume fully observed modalities, real-world applications often suffer from uncertain or missing modality inputs due to various factors. Some traditional models overly emphasize local interactions within missing modalities, neglecting the global complementary cues embedded in multimodal representations. To overcome these limitations, we propose a Dynamic Multimodal Data Fusion model based on Contrastive Learning (CL-DMDF). CL-DMDF introduces a novel attention mechanism that operates across both feature and modality dimensions to compute reliable attention scores, effectively reflecting importance at each level. The CL-DMDF further incorporates an entity-centroid contrastive learning module that constructs centroid-based positive samples from entity features to enhance discriminative learning. Additionally, an adaptive fusion module is employed to improve the efficiency and accuracy of dynamic fusion strategies. Extensive experiments conducted on three datasets demonstrate the effectiveness of the CL-DMDF across diverse multimodal fusion tasks.
Dong Li, Lingling Zhang, Binghao Han +2
School of Information, Liaoning University, Shenyang, China · School of Computer Science and Engineering, Northeastern University, Shenyang, China