Pocket TTS Indonesian

Indonesian text-to-speech with voice cloning, built on kyutai/pocket-tts and trained on 502 hours of LEMAS Indonesian speech.

Two models in this repo. Use the 6-layer one.

The student was distilled from the teacher with guidance baked in (distill_cfg_coef: 2.0), so it reaches guided quality in the single backbone pass that pocket-tts generate actually runs. The teacher only matches it with --cfg 2.0, which the shipped package cannot do — it has no cfg_coef anywhere. The teacher is kept for reproducibility and as a distillation starting point; there is no reason to run it. The CPU figures are one paired run on the same machine and text: the student is usable without a GPU and the teacher is not.

Repo layout: each model is a variant-named config beside its weights, and both share one tokenizer.

indonesian_6l.yaml   ->  6l/model.safetensors
indonesian_24l.yaml  -> 24l/model.safetensors
tokenizer.model          (shared)

Usage

uvx pocket-tts generate \
    --config hf://anak10thn/pocket-tts-indonesian/indonesian_6l.yaml@17257664e384561c957b02ac92edd1a24807f0e5 \
    --voice your_voice.wav \
    --text "Selamat pagi, semoga hari Anda menyenangkan." \
    --eos-threshold -6.0 \
    --output-path out.wav

Pass --eos-threshold -6.0. It is the best value on the eval set (9.09% median against the CLI default -4.0's 13.33%) and on long text (6.74% on an 87-word news passage). Earlier releases of this model needed two different values for those two cases -- -6.0 was best on short input but dropped whole chunks of long text -- and that split is gone since the retrain described below.

voices/ holds four CC0 Indonesian prompts from Common Voice, 48 kHz, four different speakers — pass one to --voice or bring your own recording. Omitting --voice also works and falls back to the English voice the CLI ships with.

Prompt bandwidth is the biggest lever on how distinctly a voice clones: from those 48 kHz prompts, two generations score 0.771 against each other, against 0.939 from 16 kHz YouTube prompts — where every clone comes out sounding like the same person. A quiet 48 kHz recording beats a louder compressed one. Verified from a cleared cache against both pocket-tts 3.1.0 from source and the current published wheel via uvx.

From Python:

from pocket_tts import TTSModel

model = TTSModel.load_model(
    config="hf://anak10thn/pocket-tts-indonesian/indonesian_6l.yaml@17257664e384561c957b02ac92edd1a24807f0e5"
)
state = model.get_state_for_audio_prompt("your_voice.wav")
audio = model.generate_audio(state, "Selamat pagi, semoga hari Anda menyenangkan.")

Write text the way you normally would — capitalisation and punctuation are both fine. The tokenizer case-folds internally, so Halo, Dunia! and halo, dunia! produce identical tokens.

Write numbers as words (lima belas, not 15). The training transcripts spell them out, so digits are out-of-vocabulary.

Hyphens are fine: anak-anak, tiba-tiba, rata-rata all work. They did not until 2026-09-06 — the LEMAS transcripts write reduplication as separate words, so - never entered the vocabulary and came out as an invented word in the middle of the phrase. The tokenizer's normalizer now maps a hyphen to a space, which is exactly how the corpus wrote it.

Evaluation

153 cross-sentence pairs over 116 speakers from the LEMAS Indonesian eval split, none of whose recordings appear in training. Whisper-large-v3 pinned to Indonesian, language-agnostic normalization, --temp 0.3 --n-steps 1 --cfg 1.0 — no guidance, which is what the CLI does. Both models swept over --eos-threshold on the full list and reported at their own best setting.

The student's full eos sweep, since the shape matters more than any single row:

What the retrain changed

The published student was retrained on 2026-09-10 after finding that the training targets were being cut off mid-word. The loader trims each target to the last aligned word plus a 0.2s tail, which is right for a corpus padded with silence -- but LEMAS clips are cropped tight around speech (the gap between where the signal goes quiet and the clip end has a median of -0.05s) while its aligner ends early, with speech continuing past the last aligned word by 0.15s at the median and 0.52s at p90. So 0.2s covered 62% of clips and truncated the rest. Raising it to 0.6s covers 99%.

One prediction in this it got wrong, recorded because it was wrong: the guess was that fixing truncated targets would move the eos optimum back toward the upstream reference of -1.0. It did not. -6.0 is still best, and -1.0 is bad for the opposite reason -- the model runs past the text on 19 of 153 items. The fix worked through accuracy and stability, not through EOS calibration, and why this model wants -6.0 is still unexplained.

Long text

Two paired examples, not a benchmark. First, a 73-word formal speech passage, same voice prompt and text for both models, each at its own best --eos-threshold.

The student's 4.11% is far below its 12.50% median on the eval set, which is the eval set's fault rather than a surprise: those reference transcripts are subtitle-derived, and the same ASR scores 10.08% on their real audio. On clean, properly punctuated text the model does considerably better than the evaluation suggests.

The teacher failed on a repeated structure, dropped a clause and then produced non-words:

text:       ...bukan hanya soal angka, tetapi soal bagaimana manfaatnya
            dirasakan sampai ke desa, sampai ke pasar, sampai ke meja makan...
student 6L: ...bukan hanya soal angka, tetapi soal bagaimana manfaatnya
            dirasakan sampai ke pasar, sampai ke meja makan...
teacher 24L: ...bukan hanya soal angka. Sampai kebesar, sampai kebasar, sampai ke...

Both models can drop one item from a long enumeration — the student lost "sampai ke desa" here. Split lists into separate sentences if you need every item.

Second, an 87-word news passage, student only, showing what the two fixes above are worth:

6.74% is close to this eval corpus's ASR floor of 10.08%, on text far cleaner than the corpus — which is the honest reading of what this model does on well-written input.

Read the medians, not the corpus WER. Corpus WER sums insertions over the list, so one generation that repeats itself past the end of the text outweighs whatever is under test; on this eval set adjacent eos settings swing it by 14 points while the medians move smoothly. An earlier version of this card headlined a corpus figure of 23.18% measured with guidance the CLI cannot produce, and named an eos chosen from a sweep run on the first 60 items of the list rather than a random sample. Both were wrong. The numbers above come from full-list sweeps with the ASR's language pinned.

Read WER against this corpus, not against the English models. The same ASR transcribing the eval set's real recordings scores 10.08%: the reference transcripts are subtitle-derived and the audio is YouTube-sourced. The student's 12.50% median sits close to that floor. The released English model's 0.90% is a different language on clean read speech.

Voice cloning: works, but it flattens voices

The 0.938 figure needs its anchors, and an earlier version of this card quoted it against the English models' 0.922 as if that were a fair comparison. It is not: x-vector cosines are not comparable across corpora, and on 16 kHz YouTube audio the whole scale is compressed. Measured on this eval set:

(0.888 is the four prompts used in the cloning test; 0.752 is 40 random different-speaker pairs across the set.)

Read down that table. A generation lands 89% of the way from a stranger to the target, and in a four-prompt cross test each generation was nearest its own prompt, 4 out of 4 — cloning genuinely works. But two generations made from different prompts score 0.939, essentially the same-speaker anchor. Distinct voices go in and come out sounding much more alike than they went in.

In practice: a clone resembles its target, but put two clones side by side and they sound like relatives. If you need voices that are clearly distinguishable from each other, this model will disappoint you; if you need one voice that resembles one target, it does that.

Audio quality is capped by the corpus. UTMOS 2.68 against 4.36 for the English model, because LEMAS audio is 16 kHz while Mimi runs at 24 kHz: there is no energy above 8 kHz to learn. Expect a decent phone call or YouTube video, not a studio recording. Mixing in 48 kHz Indonesian speech would move this; more training does not.

CPU and screen readers: ONNX INT8

An INT8 ONNX conversion of the 6-layer model lives under onnx/, for the native PocketTTS.cpp runtime and for anything that cannot carry PyTorch. Converted and validated by Jim Grimsby Jr. of Sonata Sherpa Voices, an NVDA screen-reader synthesizer add-on, from revision 17257664e384561c957b02ac92edd1a24807f0e5.

Measured on an older Windows desktop limited to two CPU threads: mean first-audio 45.5 ms, and 17.84 s of audio generated in 3.288 s. Short utterances, numbers, punctuation, multi-chunk long text, cancellation and recovery after cancellation all completed under NVDA. onnx/VALIDATION.txt is his full report.

That validation used --eos-threshold -2.0 rather than the -6.0 recommended above, deliberately: a screen reader must never truncate an isolated character or a short notification, and a less negative threshold makes EOS harder to trigger. Testing short strings here found no truncation at either value, so treat it as a tradeoff rather than a correction — at -2.0 the sentence eval had 9 of 153 generations emit no EOS and run to the length cap, which is sound continuing past the text.

The bundle ships no voice embedding: bring your own prompt, or convert one of the CC0 prompts in voices/. The conversion originally included one derived from kyutai/tts-voices, which is a gated repository, so it is not redistributed here.

Training

• Teacher: kyutai/pocket-tts English 24L, text embedding reinitialised for the new tokenizer, backbone transferred. Stopped at step 87,500 of a planned 250,000 once it plateaued — validation loss was flat from step 42,500 on.
• Student: depth distillation to 6 layers with distill_cfg_coef: 2.0, 50,000 steps, lr 4e-4 cosine, data.trail_sec: 0.6. Validation loss was still falling at the end, so it is not saturated. distill_cfg_coef is the measured optimum, not a default: swept on the teacher over 1/2/3/4/6 it peaks at 2.0 on similarity, WER and UTMOS at once, and at 6.0 the model is silent on 124 of 153 inputs.
• Data: 502 h / 298,652 utterances, one shard of LEMAS Indonesian filtered to duration >= 4 s and mean alignment confidence >= 0.8, split by recording.
• Transcripts: LEMAS Indonesian text is ALL CAPS with no punctuation. Punctuation and truecasing were restored with 1-800-BAD-CODE/xlm-roberta_punctuation_fullstop_truecase before fitting the tokenizer, so the model learns comma pauses and sentence-final intonation and users' punctuation is in-vocabulary.
• Tokenizer: 4000-piece BPE, nmt_nfkc_cf normalization (case folding baked into the .model). Shared by both models.
• Hardware: one shared Tesla T4. fp16 autocast with a GradScaler — Turing has no bf16 tensor cores, and bf16 measures 11x slower there. Teacher ~8 days at 0.29 steps/s, student ~1.2 days at 0.46 steps/s.

Code — the data pipeline, the fp16 patch, and the eval fixes the numbers above depend on: anak10thn/pocket-tts, branch indonesian, merged up to pocket-tts 3.1.0. It is kept on the fork rather than upstream by agreement with the maintainers.

Limitations

• 16 kHz-sourced audio: band-limited output, UTMOS 2.68.
• Two of 153 eval items produce silence at the recommended setting. If a line comes back empty, retry or nudge --eos-threshold toward -5.0.
• Digits are out-of-vocabulary; spell numbers out.
• Trained on YouTube speech — mostly conversational and broadcast Indonesian. Formal narration is out of domain.
• Regional accents and languages other than Indonesian are not covered.
• The exclamation mark ! is out-of-vocabulary (the restored transcripts use . , ? almost exclusively).
• On long text the model occasionally drops one item from an enumeration.

License and credits

CC-BY-4.0, following the LEMAS training data. Model architecture and base weights from Kyutai — see the CALM paper. Training data from the LEMAS Project.