Decoder-only Conformer with Modality-aware Sparse Mixtures of Experts for ASR
On the map: Mixture-of-experts → Multimodal MoE models
Abstract (arXiv)
We present a decoder-only Conformer for automatic speech recognition (ASR) that processes speech and text in a single stack without external speech encoders or pretrained large language models (LLM). The model uses a modality-aware sparse mixture of experts (MoE): disjoint expert pools for speech and text with hard routing and top-1 selection, embedded in hybrid-causality Conformer blocks (bidirectional for speech, causal for text). Training combines CTC on speech positions with label-smoothed cross-entropy for text generation. Our 113M-parameter model consistently improves WER over a 139M AED baseline on Librispeech (2.8% vs. 3.2% test-clean; 5.6% vs. 6.0% test-other). On Common Voice 16.1 with a single multilingual model across five languages, our approach reduces average WER from 12.2% to 10.6%. To our knowledge, this is the first randomly initialized decoder-only ASR that surpasses strong AED baselines via modality-aware routing and sparse MoE, achieving better accuracy with fewer active parameters and without alignment/adaptation modules.
Key facts. No citing papers in the map yet (data through 14 Oct 2026). Placed in Multimodal MoE models, one of 12 directions in Mixture-of-experts. Builds on 27 of its 31 references that are in the map. First posted on arXiv 13 Feb 2026.
Builds on
27 of 31 references.
Closest ancestors · 3
Same direction, newest first
- 2024MoMa: Efficient Early-Fusion Pre-training with Mixture of Modality-Aware Experts31 Jul
- 2022Multimodal Contrastive Learning with LIMoE: the Language-Image Mixture of Experts6 Jun
- 2021SpeechMoE: Scaling to Large Acoustic Models with Dynamic Routing Mixture of Experts7 May
Other references · 24
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- 2017Outrageously Large Neural Networks: The Sparsely-Gated Mixture-of-Experts Layercited by 3,509
- 2021Switch Transformers: Scaling to Trillion Parameter Models with Simple and Efficient Sparsitycited by 3,073
- 2020Conformer: Convolution-augmented Transformer for Speech Recognitioncited by 1,863
- 2019Common Voice: A Massively-Multilingual Speech Corpuscited by 1,384
- 2019SpecAugment: A Simple Data Augmentation Method for Automatic Speech Recognitioncited by 1,380
- 2023Qwen-Audio: Advancing Universal Audio Understanding via Unified Large-Scale Audio-Language Modelscited by 608
- 2023SpeechGPT: Empowering Large Language Models with Intrinsic Cross-Modal Conversational Abilitiescited by 529
12 more
- 2021VLMo: Unified Vision-Language Pre-Training with Mixture-of-Modality-Expertscited by 425
- 2023AudioPaLM: A Large Language Model That Can Speak and Listencited by 343
- 2023On decoder-only architecture for speech-to-text and large language model integrationcited by 145
- 2023Textually Pretrained Speech Language Modelscited by 101
- 2020Developing Real-time Streaming Transformer Transducer for Speech Recognition on Large-scale Datasetcited by 97
- 2021BigSSL: Exploring the Frontier of Large-Scale Semi-Supervised Learning for Automatic Speech Recognitioncited by 88
- 2023SLM: Bridge the thin gap between speech and text foundation modelscited by 67
- 2021Efficient conformer: Progressive downsampling and grouped attention for automatic speech recognitioncited by 42
- 2024Efficient Streaming LLM for Speech Recognitioncited by 12
- 2024AlignFormer: Modality Matching Can Achieve Better Zero-shot Instruction-Following Speech-LLMcited by 12
- 2023Speech-to-Text Adapter and Speech-to-Entity Retriever Augmented LLMs for Speech Understandingcited by 9
- 2024Exploring the limits of decoder-only models trained on public speech recognition corporacited by 5
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- 2022Parameter-Efficient Conformers via Sharing Sparsely-Gated Experts for End-to-End Speech Recognition
- 2025GLAD: Global-Local Aware Dynamic Mixture-of-Experts for Multi-Talker ASR
- 2026Rethinking Entropy Allocation in LLM-based ASR: Understanding the Dynamics between Speech Encoders and LLMs
- 2024U2++ MoE: Scaling 4.7x parameters with minimal impact on RTF
- 2026Mixture-of-Experts with Intermediate CTC Supervision for Accented Speech Recognition
- 2025Omni-Router: Sharing Routing Decisions in Sparse Mixture-of-Experts for Speech Recognition