Joint Learning Global-Local Speaker Classification to Enhance End-to-End Speaker Diarization and Recognition
Organizations: Soul AI Lab, China · X-LANCE Lab, Shanghai Jiao Tong University, China
Abstract
Large Audio-Language Models (LALMs) have demonstrated remarkable performance in end-to-end speaker diarization and recognition. However, their speaker discriminability remains limited due to the scarcity of large-scale conversational data and the absence of explicit speaker representation optimization. To address this, we propose GLSC-SDR, a paradigm that jointly trains speaker classification with diarization and recognition. We further introduce a Global-Local Speaker Classification strategy, which uses clustered speakers as global labels and re-encoded intra-cluster speakers as local labels. This hierarchical design enhances fine-grained speaker discrimination while preserving semantic transcription accuracy. Experiments on AliMeeting, AISHELL-4, and AMI-SDM demonstrate that GLSC-SDR achieves competitive or superior performance compared to simulation-based and multi-encoder approaches, without relying on large-scale real conversational data.
Figures & tables
| Model | Alimeeting | AISHELL-4 | AMI-SDM | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WER↓ | cpWER↓ | cp↓ | SCA↑ | WER↓ | cpWER↓ | cp↓ | SCA↑ | WER↓ | cpWER↓ | cp↓ | SCA↑ | |
| Related work | ||||||||||||
| TagSpeech [ 7 ] | 25.42 | 33.84 | 8.42 | 81.63 | - | - | - | - | 31.62 | 42.55 | 10.93 | 70.01 |
| VibeVoice-ASR [ 18 ] | 27.4 | 29.33 | 1.93 | - | 21.4 | 24.99 | 3.59 | - | 24.65 | 28.82 | 4.17 | - |
| Gemini-2.5-pro* | 27.43 | 41.64 | 14.2 | - | 22.42 | 31.59 | 9.17 | - | 22.35 | 34.78 | 12.43 | - |
| Gemini-3-pro* | 26.75 | 32.84 | 6.09 | - | 22.75 | 27.43 | 4.68 | - | 22.09 | 26.91 | 4.82 | - |
| Classification Method | WER↓ | cpWER↓ | cp↓ | SCA↑ |
|---|---|---|---|---|
| GSC-SDR | 22.61 | 30.81 | 8.2 | 78.56 |
| SC-SDR | 22.83 | 30.8 | 8.06 | 78.56 |
| GLSC-SDR | 22.71 | 29.93 | 7.22 | 79.74 |
| exp_group | cluster num | WER | cpWER | cp | SCA |
|---|---|---|---|---|---|
| baseline | - | 23.33 | 32.18 | 8.85 | 77.84 |
| GLSC_Kmeans | 50 | 23.05 | 31.53 | 8.48 | 72.2 |
| GLSC_Kmeans | 200 | 22.58 | 30.32 | 7.74 | 78.58 |
| GLSC_Kmeans | 430 | 22.7 | 31.28 | 8.23 | 78.02 |
| GLSC_HDBSCAN | 430 | 22.71 | 29.93 | 7.22 | 79.74 |
Speaker Diarization
Speaker diarization identifies who spoke when in audio, including speaker changes, overlapping speech, and speaker identity across conversations.
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