Phonology-Aware Speaker Extraction Frontend for Audio LLMs
Organizations: Sun Yat-Sen University, Zhuhai, China · Beijing Normal-Hong Kong Baptist University, Zhuhai, China · Fudan University, Shanghai, China
Abstract
Target speaker extraction (TSE) is a key frontend for enabling audio large language models (LLMs) to recognize and understand a designated speaker in overlapping speech. However, multilingual mixtures exhibit heterogeneous extraction demands, causing fixed-depth systems to either under-process challenging inputs or waste computation on inputs that have already converged. Existing TSE frontends generally apply uniform computation, while Audio-LLM adaptation methods neither explicitly model language-conditioned extraction demands nor preserve plug-and-play compatibility with frozen downstream models. We therefore propose LATTE, a lightweight 5.2M-parameter frontend that combines an acoustic Difficulty Estimator, a task-adaptive phonology-informed prior learned from multi-depth TSE gains, and an Adaptive Hourglass Extractor to route each mixture without requiring language identity at inference. On PolyExtract, LATTE achieves a macro SI-SNRi of 15.07 dB at 0.30 GFLOPs, retaining performance within 0.09 dB of a 0.53-GFLOP fixed-depth model while reducing computation by 43.4%, and lowers the average WER from 16.8% to 14.6% relative to TF-GridNet. By jointly modeling sample-level extraction demands and phonological structure, LATTE provides a practical framework for quality-aware, compute-efficient multilingual TSE and offers a scalable path toward robust Audio-LLM deployment.
Figures & tables
| Language | Key Phonological Features | PDI |
| English | non-tonal, moderate clusters | 0.15 |
| Turkish | agglutinative, 8-way vowel harmony | 0.30 |
| Mandarin | 4 tones, simple onsets | 0.35 |
| Polish | complex clusters ( szcz- , prz- ) | 0.42 |
| Kinyarwanda | 2 Bantu tones, prenasalized stops | 0.48 |
| Cantonese | 6–9 tones, checked codas | 0.55 |
| SpEx+ | TD- SB | AD-Flow TSE | TCE | TF-GridNet | LATTE | |
| Model Complexity | ||||||
| Trainable Params | 11.1M | 14.4M | 85.0M | 8.7M | 14.5M | 5.2M |
| Avg. GFLOPs | 0.62 | 0.74 | 5.80 | 0.55 | 1.42 | 0.30 |
| All Directed Language Pairs | ||||||
| Macro SI-SNRi | 12.8 | 13.2 | 14.6 | 13.5 | 13.8 | 15.07 |
| Macro PESQ | 2.92 | 2.98 | 3.14 | 3.01 | 3.06 | 3.22 |
| Language | Metric | LoRA | Plugin | |||
| Qwen3 Omni | Whisper v3 | DeSTA 2.5-A | Voice Filter | LATTE | ||
| PolyExtract | WER | 15.4 | 18.8 | 15.6 | 20.6 | 14.6 |
| FLOPs | 18.2T | 4.8T | 12.6T | 0.6T | 0.3T | |
| Chinese | CER | 11.8 | 13.5 | 12.9 | 17.8 | 12.6 |
| FLOPs | 18.2T | 4.8T | 12.6T | 0.6T | 0.3T | |
| English | WER | 7.9 | 8.9 | 8.1 | 12.3 | 8.2 |
| PolyExtract (Avg.) | Mandarin | English | |||||||||
| Category | Method | Trainable Params | Mix WER | Ext. WER | RelRed | Mix CER | Ext. CER | RelRed | Mix WER | Ext. WER | RelRed |
| LoRA | Qwen3-Omni [ 22 ] | 7.0B | 38.5 | 15.4 | 60.0% | 32.4 | 11.8 | 63.6% | 24.6 | 7.9 | 67.9% |
| Whisper-v3 [ 16 ] | 1.5B | 38.5 | 18.8 | 51.2% | 32.4 | 13.5 | 58.3% | 24.6 | 8.9 | 63.8% | |
| DeSTA2.5-Audio [ 11 ] | 7.2B | 38.5 | 15.6 | 59.5% | 32.4 | 12.9 | 60.2% | 24.6 | 8.1 | 67.1% | |
| Plug-in | VoiceFilter [ 14 ] | 8.2M | 38.5 | 20.6 | 46.5% | 32.4 | 17.8 | 45.1% | 24.6 | 12.3 | 50.0% |
| TD-SpeakerBeam [ 4 ] | 14.4M | 38.5 | 19.8 | 48.6% | 32.4 | 16.9 | 47.8% | 24.6 | 11.4 | 53.7% | |
| Task A:Slot Filling | Task B:Yes/No | Task C:Attribution | ||||||||||
| System | en | zh | yue | Poly. | en | zh | yue | Poly. | en | zh | yue | Poly. |
| Mix Qwen | 24 | 21 | 15 | 20 | 61 | 58 | 51 | 57 | 43 | 40 | 33 | 39 |
| LoRA Qwen | 70 | 57 | 47 | 58 | 88 | 77 | 67 | 77 | 85 | 70 | 59 | 71 |
| LATTE Qwen | 58 | 55 | 49 | 54 | 78 | 75 | 69 | 74 | 72 | 68 | 61 | 67 |
| Clean Qwen | 74 | 69 | 61 | 68 | 91 | 89 | 83 | 88 | 89 | 85 | 79 | 84 |
| Variant | Avg | Hard | GFLOPs |
| LATTE-Full | 15.1 | 14.6 | 0.30g |
| Adaptive compute | |||
| W/o DE (Fixed-6) | 13.5 | 11.8 | 0.53g |
| W/o refinement | 14.3 | 12.5 | 0.28g |
| W/o | 14.9 | 13.0 | 0.39g |
| DE design | |||
Target Speaker Extraction
Target speaker extraction isolates a chosen voice from overlapping speech using speaker identity, visual, spatial, textual, or neural cues.
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