---
license: cc-by-4.0
language:
  - th
tags:
  - n-gram
  - kenlm
  - shallow-fusion
  - automatic-speech-recognition
  - Thai
---

# Typhoon ASR Streaming 115M — paired 4-gram fusion LM

KenLM **4-gram over sub-word tokens** (2048 Thai BPE) for decode-time shallow fusion with
[`typhoon-ai/typhoon-asr-streaming-115m`](https://huggingface.co/typhoon-ai/typhoon-asr-streaming-115m).
Trained on the ASR training transcripts plus a synthetic in-domain corpus (English
code-switch terms inserted into LLM-generated Thai carrier templates) — **no evaluation
data**. Tokenizer-locked: it works only with the matching model's tokenizer.

File: `ngram_4gram_bpe2048.arpa` (~2.7 GB, KenLM ARPA).

## Usage

Enable n-gram fusion in the streaming greedy decoder (see the
[project repo](https://github.com/warit-s/typhoon-asr-streaming),
`docs/SHALLOW_FUSION.md`):

```python
from omegaconf import OmegaConf

cfg = {"strategy": "greedy_batch", "greedy": {
    "ngram_lm_model": "ngram_4gram_bpe2048.arpa",
    "ngram_lm_alpha": 0.5,
}}
model.change_decoding_strategy(OmegaConf.create(cfg))
```

Fusion re-ranks candidates inside the streaming decoder and changes the real-time factor
by under 3%. Typical weight range: 0.3 (broad domain) – 0.7 (tight in-domain).

## License

**CC-BY-4.0**, matching the paired acoustic model. Built by SCB DataX for the Typhoon ASR Streaming project.