Temporal-Coupled Flow Matching for Speech Continuation
This repository contains the three formally evaluated
Temporal-Coupled Flow Matching (TCFM) FlowHead adapters for speech
continuation. TCFM preserves the Flow-SLM sampler, Mimi codec, Transformer,
and semantic pathway. It fine-tunes only 488,448 LoRA parameters in the
FlowHead by adding speech-time endpoint-trajectory supervision to conditional
flow matching.
Code and complete reproduction instructions:
https://github.com/JoyBoyuuu/TCFM
Required base model
These files are adapters, not standalone 1.3B-parameter models. Inference
requires the Flow-SLM 1B-extended base checkpoint distributed by the
Flow-SLM authors. Download it with:
1git clone https://github.com/JoyBoyuuu/TCFM.git
2cd TCFM
3conda env create -f environment.yml
4conda activate tcfm
5python scripts/download_assets.py --checkpoint-dir checkpoints \
6 --cache-dir cache/huggingface
Released checkpoints
| File | Training seed | Best validation step |
|---|
tcfm_adapter_seed_42.pt | 42 | 2,000 |
tcfm_adapter_seed_1234.pt | 1,234 | 1,800 |
tcfm_adapter_seed_2026.pt | 2,026 | 1,900 |
The three training runs all completed 2,000 optimizer steps. The released
checkpoint for each seed is the one with the lowest validation objective.
The files are path-free, inference-only exports: optimizer state, random
number generator state, absolute cluster paths, and duplicated LoRA state
are excluded. manifest.json records SHA-256 hashes and adapter settings.
Training data and objective
- Base model: Flow-SLM 1B-extended.
- Adaptation data: 4,096 eligible utterances from LibriSpeech
train-clean-100.
- Validation data: 256 eligible utterances from LibriSpeech
dev-clean.
- Each example uses a 3-second prefix and a 5-second future segment.
- LoRA rank 4, alpha 8, dropout 0.05.
- Batch size 8, learning rate
5e-5, weight decay 1e-4.
- TCFM transition weight 0.1 and prefix-boundary weight 0.1.
- Curvature weight 0.5, direction weight 0.1, boundary window 16 frames.
TCFM reconstructs the clean endpoint implied by the predicted FlowHead
velocity and regularizes endpoint displacement, curvature, movement
direction, and prefix-continuation boundary behavior along speech time. See
the code repository for the complete mathematical objective.
Inference
Download one adapter:
1from huggingface_hub import hf_hub_download
2
3adapter = hf_hub_download(
4 repo_id="NYCU-MLLab/Temporal-Coupled-Flow-Matching-for-Speech-Continuation",
5 filename="tcfm_adapter_seed_42.pt",
6)
7print(adapter)
Then run a smoke evaluation on a GPU/Slurm compute node:
1export AUDIO_ROOT=/path/to/LibriSpeech
2
3sbatch --account=<account> --partition=<gpu-partition> \
4 --export=ALL,PROJECT_DIR="$PWD",AUDIO_ROOT="$AUDIO_ROOT",\
5METHOD=tcfm_adapter,TRAINING_SEED=42,LIMIT=10,\
6ADAPTATION_CKPT=/path/to/tcfm_adapter_seed_42.pt,PROTOCOL=open_ended \
7 scripts/slurm/infer_1gpu.sbatch
The reported decoder uses 32 Euler flow steps, 16 Mimi RVQ stages, acoustic
and semantic temperatures 0.8, top-p 0.95, and CFG scale 0.3.
Evaluation summary
The formal campaign evaluates all three training seeds on LibriSpeech
test-clean and test-other with three matched inference seeds. Selected
adapter-level results relative to Base Flow-SLM are:
- open-ended speaker similarity:
0.909415 -> 0.912781, paired effect
+0.003367 with 95% CI [+0.002298, +0.004455];
- open-ended natural-calibrated 200-ms boundary log-mel distance:
8.5462 -> 8.4945, effect -0.05175 with 95% CI
[-0.07862, -0.02511];
- open-ended WavLM FSD:
3.653 -> 2.919, about 20% lower;
- oracle-semantic Mimi q0 frame agreement:
0.65553 -> 0.66977, effect
+0.01424 with 95% CI [+0.01265, +0.01576];
- oracle-semantic WavLM FSD:
0.590 -> 0.533, about 9.8% lower.
These results support improved continuation stability, speaker persistence,
and distributional acoustic match. They do not establish universal boundary
improvement, human preference, or broad lexical/syntactic improvement.
Only three training seeds were evaluated.
Intended use and limitations
The adapters are research artifacts for English speech continuation and for
reproducing the TCFM experiments. They should not be treated as a speech
recognizer, a semantic dialogue model, or a production voice-cloning system.
Generated speech may contain incorrect, unstable, or biased content. Obtain
consent before processing or imitating a person's voice.
Attribution and licensing
TCFM is derived from Flow-SLM. The upstream Flow-SLM revision used for this
work did not include a license file, so this release does not assert a new
license over inherited architecture or base-model assets. The Flow-SLM base
checkpoint and third-party datasets are not redistributed here and remain
subject to their original terms. See the repository NOTICE.md for details.