A benchmark can rank models and still fail to tell you whether the ground truth deserves trust.
Most ASR benchmarks start with the model. We started with a more basic question: can we trust the dataset?
Dataset.ET Amharic Speech v0.1.0 is a new open corpus with 22.7 hours of read speech, 7,405 clips, and 320 contributors. Its test split contains 718 clips from 34 speakers, totaling 2.22 hours. No speaker or prompt in the test split appears in training or validation.
That design looks good on paper. We wanted evidence from the audio itself. So we ran the same test split through seven speech-to-text systems: Addis AI STT, Google Chirp 3, three Addis Scribe variants, a compact 0.6B baseline, and Meta MMS-1B.
Every system received identical audio and references. Every output went through the same Amharic normalization and jiwer scoring pipeline. None of the systems was trained or tuned on this test set.
The result in one line
The dataset holds up. Addis AI STT led at WER 25.0 and CER 8.2, followed by Google Chirp 3 at WER 32.9 and CER 14.3. Those character error rates would be difficult to reach if the audio and references were broadly misaligned.
The full results
We ranked the systems by Word Error Rate. Lower CER and WER are better. The table reports the benchmark result after applying the same normalization to every system.
| Rank | System | CER | WER | Assessment |
|---|---|---|---|---|
| 1 | Addis AI STT | 8.20 | 25.0 | Strong |
| 2 | Google Chirp 3 | 14.30 | 32.9 | Strong |
| 3 | Addis Scribe md | 24.91 | 41.8 | Fair |
| 4 | Addis Scribe sm | 25.80 | 44.0 | Fair |
| 5 | Addis Scribe base | 27.50 | 48.1 | Fair |
| 6 | Compact ASR (0.6B) | 19.30 | 49.6 | Word-weak |
| 7 | Meta MMS-1B | 16.21 | 52.0 | Word-weak |
Word Error Rate
Identical test audio and scoring. Shorter bars are better.
Addis AI STT finished 7.9 WER points ahead of Chirp 3. Addis Scribe md led the compact tier at 41.8, 16.8 points behind the top result. That is a real separation, but the leaderboard is only half of what this run tells us.
The dataset passed the harder test
A best WER of 25.0 can trigger an obvious suspicion: maybe the reference labels are wrong. We checked that directly.
Script quality
0%
of references fell below a 0.85 Ethiopic-script ratio
Latin characters
1%
of references contained any Latin characters
Independent alignment
8.2 / 14.3
CER from the two production systems
The references are clean, formal Amharic. More importantly, strong recognizers track them closely at the character level. When two independent production systems reach CER 8.2 and 14.3 on the same external split, the audio and labels are not broadly drifting apart.
The corpus construction supports that result. Contributors read known prompts, validators checked whether each recording matched, clips with any reject vote were excluded, and the remaining audio went through acoustic screening. The test split is also speaker-disjoint and prompt-disjoint.
That is enough evidence for us to treat this as a credible neutral test set. It is not a perfect representation of every kind of Amharic speech, but the ground truth is usable.
WER is also measuring transcription style
The raw WER numbers are honest, but they need context. A meaningful share of the errors comes from formatting differences rather than failed recognition.
Reference
ይህም ባለፈው ዓመት ከተመረተው 4 ነጥብ 7 ሜትር ኪዩብ የውሃ አቅርቦት አንፃር ሲታይ የ7 ነጥብ 6 በመቶ ብልጫ እንዳለው
Recognizer
ይህም ባለፈው አመት ከተመረተው 4.7 ሜትር ኪዩብ የውሃ አቅርቦት አንፃር ሲታይ የ7.6 በመቶ ብልጫ እንዳለው
The content is the same. The reference spells out 4 ነጥብ 7 and 7 ነጥብ 6; the recognizer writes 4.7 and 7.6. WER counts those as errors even though the transcript remains correct for a reader.
The same thing happens with joined and split compounds, hyphens, punctuation, and common spelling variants. In this test set, 21% of references contain digits and 16% contain punctuation that compact models were not trained to emit consistently.
A genuine recognition error
The reference says ማስተርስ. One recognizer outputs 10. This changes the word and the meaning, so it belongs in the error count.
We kept the reported scores unchanged. A benchmark becomes less useful when the normalization is quietly tuned after seeing the outputs. A second score with explicit number and punctuation normalization would still be useful, but it should sit next to the reported result, not replace it.
What the model spread tells us
Production systems generalize better
Addis AI STT and Google Chirp 3 occupy the top tier on external Amharic audio. Neither system saw this test set during training or tuning. The result is evidence of broader coverage, not familiarity with one benchmark distribution.
The compact tier is useful, but there is still a gap
Addis Scribe md is the best compact model measured at WER 41.8. The sm and base variants follow at 44.0 and 48.1. These models can produce useful Amharic transcripts, but out-of-distribution coverage still separates them from the production APIs.
CER and WER expose different failures
Meta MMS-1B reaches CER 16.21, better than every Addis Scribe variant on characters, yet finishes last on WER at 52.0. The compact 0.6B baseline shows the same pattern with CER 19.30 and WER 49.6.
Those systems are hearing much of the acoustic content, but word boundaries and transcript formatting remain weak. CER alone makes them look stronger than the transcripts feel. WER alone hides how much of the underlying speech they captured. For Amharic, we need both.
What this dataset can and cannot measure
The full release is useful because it is open, licensed under CC BY 4.0, and explicit about how it was collected. The 7,405 clips are 16 kHz audio with speaker metadata, acoustic measurements, peer-validation votes, and speaker-disjoint splits.
Its limits are equally important. This is read speech, not conversation. The prompts lean formal and toward current affairs. Contributors skew young and urban: 75.1% of clips come from people aged 18 to 24, and 47.5% come from Addis Ababa. The original recordings also passed through Telegram voice messages, so device and codec artifacts are part of the corpus.
A model that scores well here has handled clean, prompted Amharic across held-out speakers. That does not automatically tell us how it handles phone calls, overlapping speech, rural accents, code-switching, or spontaneous conversation.
Use the benchmark for what it measures
This is a credible test of read Amharic speech and out-of-distribution generalization. It is not a complete benchmark for Amharic in the wild.
Method
| Item | Setting |
|---|---|
| Test data | snapwre/amharic-speech test split, 718 clips, 2.22 hours, 16 kHz |
| References | Dataset sentence field, formal read-speech register |
| Scoring | CER and WER via jiwer, with the same Amharic normalization for every output |
| Compact models | Greedy decoding, deterministic settings, single-GPU inference |
| Addis AI STT | Production API, language_code=am, one request per clip |
| Google Chirp 3 | Cloud Speech-to-Text v2, am-ET, one request per clip |
| Training overlap | No measured system was trained or tuned on this test split |
Two answers from one benchmark
The model result is straightforward. Addis AI STT led the field at WER 25.0 and CER 8.2, with Google Chirp 3 second. Addis Scribe md led the compact tier.
The dataset result matters beyond our own models. Independent systems align closely with its references, the test design avoids speaker and prompt overlap, and the remaining errors are explainable. snapwre/amharic-speech is a dataset we can train on and benchmark against with confidence, as long as we stay honest about the type of speech it represents.