DAMOS: Learning Distortion-Aware Speech Quality Assessment through Explicit Distortion Localization
Authors: Naiyuan Li, Li Dong, Diqun Yan
Organizations: College of Information Science and Engineering, Ningbo University, Ningbo, China · College of Artificial Intelligence, Ningbo University of Finance and Economics, Zhejiang Provincial Collaborative Innovation Center for Digital Supply Chain and Artificial Intelligence of Bulk Commodities
Automatic speech quality assessment aims to predict Mean Opinion Scores (MOS) consistent with human subjective perception and is essential for evaluating speech generation, enhancement, and communication systems. For speech signals, especially synthetic speech, distortions often occur locally, and overall perceptual quality is usually dominated by a small number of perceptually salient distortion regions. However, most existing methods are primarily optimized with utterance-level MOS, which provides only coarse-grained supervision and offer no explicit indication of where perceptually important distortions occur. To address this limitation, we introduce explicit distortion localization as auxiliary knowledge for speech quality assessment. We construct the first partially distorted speech dataset with frame-level distortion annotations and train a localization model to generate distortion cues. Building on these cues, we propose DAMOS, a distortion-aware speech quality assessment framework that integrates localization information into the MOS prediction pipeline. Experiments on multiple public benchmarks demonstrate that DAMOS consistently outperforms existing methods and exhibits strong cross-dataset generalization, validating the effectiveness of explicit distortion localization for speech quality assessment.
Figures & tables
Class
Type
Samples
Ratio (%)
–
Clean
406
2.7
A1
Codec (single)
1,327
8.8
A2
Codec tandem
693
4.6
A3
Low-bitrate compression
871
5.8
A4
Resampling
565
3.8
A5
Reverberation
1,411
9.4
TABLE I: Distortion type distribution in the synthetic dataset (actual generated statistics).
Fig. 1: Architecture of the proposed DAMOS.
Method
PSTN
Tencent
NISQA_FOR
NISQA_LIVETALK
NISQA_P501
SRCC
LCC
SRCC
LCC
SRCC
LCC
SRCC
LCC
SRCC
LCC
NISQA
0.819
0.818
0.943
0.946
0.876
0.891
0.755
0.778
0.907
0.904
SSL-MOS
0.816
0.812
0.959
0.960
0.859
0.857
0.674
0.696
0.902
0.895
MOSA-Net+
0.816
0.812
0.936
0.937
0.863
0.863
0.633
0.633
0.876
0.887
DNSMOS Pro
0.799
0.797
0.918
0.923
0.754
0.760
0.519
0.512
0.864
0.824
SLL-Conformer [ 39 ]
0.825
0.822
0.952
0.954
0.904
0.914
0.759
0.778
0.926
0.928
TABLE III: performance comparison on the NISQA, PSTN and Tencent datasets.
Model
TCD-VoIP [ 8 ]
NISQA_P501
NISQA_LIVETALK
NISQA_FOR
Tencent
PSTN
SOMOS [ 11 ]
Avg.
LDNet
0.734
0.611
-0.092
0.393
0.328
0.578
-0.030
0.360
NISQA
0.561
0.519
0.236
0.359
0.241
0.433
0.111
0.351
SSL-MOS
0.750
0.847
0.680
0.737
0.675
0.736
0.435
0.694
UTMOS
0.775
0.890
0.792
0.798
0.714
0.749
0.307
0.718
MOSA-Net+
0.828
0.816
0.629
0.685
0.755
0.736
0.387
0.691
DNSMOS Pro
0.554
0.584
0.147
0.275
0.465
0.576
0.055
0.379
TABLE IV: Cross-corpus generalization results: SRCC comparison across datasets.
Method
BVCC
TCD-VoIP
NISQA_P501
NISQA_LIVETALK
NISQA_FOR
Tencent
PSTN
SOMOS
Avg
Last Hidden Layer
0.853
0.735
0.826
0.333
0.480
0.687
0.630
0.380
0.616
Best Hidden Layer
0.887
0.851
0.827
0.727
0.767
0.719
0.740
0.405
0.740
Average of All Layers
0.876
0.815
0.855
0.759
0.825
0.791
0.742
0.399
0.758
DAMOS (DSLA)
0.885
0.860
0.856
0.781
0.808
0.742
0.738
0.435
0.763
TABLE VI: Analysis of different hidden-layer aggregation strategies. All models evaluated using utterance-level SRCC.
Fig. 2: Average normalized layer weights learned by the proposed Distortion-Sensitive Layer Adaptation (DSLA) on different speech quality assessment datasets.
Class
Frame-level
Boundary
EER(%)
F1
Acc
Prec
Rec
EER(%)
F1
Acc
Prec
Rec
all
15.77
0.807
0.903
0.963
0.695
13.61
0.742
0.976
0.887
0.638
A1
16.40
0.819
0.906
0.976
0.705
12.74
0.762
0.979
0.909
0.656
A2
14.57
0.775
0.894
0.965
0.648
16.35
0.683
0.972
0.835
0.578
A3
12.87
0.838
0.920
0.944
0.753
12.79
0.802
0.981
0.934
0.703
A4
19.27
0.767
0.897
0.953
0.642
9.47
0.793
0.983
0.873
0.727
TABLE VII: Results of Per-distortion-class frame-level and boundary detection metrics
Dataset
Mask Condition
MSE
SRCC
LCC
BVCC
Normal mask
0.191
0.885
0.884
Zero mask
0.191
0.884
0.884
One mask
0.227
0.870
0.872
TCD-VoIP
Normal mask
0.300
0.837
0.858
Zero mask
0.304
0.829
0.858
One mask
0.374
0.818
0.845
TABLE VIII: Effect of distortion localization guidance under different mask conditions.
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