Benchmarks

How Addis Voice 2 measures up
on Amharic speech.

A public, reproducible evaluation of Amharic text to speech across 100 prompts drawn from open datasets.

Amharic prompts
100
Systems compared
7
Run date
12 August 2026
Summary

Every measure, in one table

Every measure from this run, with the leading system in each row highlighted. Where another system leads, its cell is highlighted rather than left out.

Addis Voice 2 leadsAnother system leads
Every measure in this benchmark run, with the leading system in each row highlighted.
MeasureAddis Voice 2Azure AmehaGemini 3.1 Flashgpt-4o-mini-ttsElevenLabs v3Meta MMS
Composite scoreAmharic, 100 clips, blind, 1 to 5, higher is better4.253.493.842.552.003.03
Character error rate87 prompts, ASR judge, lower is better4.44%3.03%2.89%18.74%111.65%7.86%
Word error rate87 prompts, ASR judge, lower is better13.87%11.16%11.02%31.34%147.86%22.89%
NaturalnessAmharic, blind listening axis, higher is better4.012.543.901.201.003.09
Intelligibility, rated by earAmharic, blind listening axis, higher is better4.804.493.963.471.232.84
Voice qualityAmharic, blind listening axis, higher is better3.943.443.672.983.773.17
Latency, p50Amharic, median request time, not adjusted for clip length, lower is better5.40s1.05s8.94s3.80s9.97s7.01s

Azure ships two Amharic voices. The stronger is shown.

Two measurements, two different answers

A speech system has to be understood and it has to sound like a person. We publish both rankings side by side because they measure different properties of speech quality.

Result 1

Intelligibility: 4th of 7 synthetic TTS systems

Scored by running every clip through a speech recognition judge and measuring how far the transcript drifts from the prompt. Addis Voice 2 records 4.44% CER and 13.87% WER. Gemini 3.1 Flash TTS and Azure Ameha Neural score lower error on this proxy, and their confidence intervals overlap ours.

Read the method and the full table
Result 2

Listening quality: highest on all three axes

In a blind pass over the same clips, Addis Voice 2 rates highest of every system tested on naturalness 4.01, intelligibility 4.80 and voice quality 3.94, each out of 5.

Read the method and the full table

Recognition error measures transcript accuracy, while the listening evaluation measures perceived speech quality.

Systems

What was tested, and under what conditions

Systems without documented Amharic synthesis support are included as unsupported-language conditions and should be interpreted in that context.

SystemModelVoiceCondition
Addis Voice 2Production standard checkpoint.addis-voice-2am-yohanes-calmDocumented language support
Azure Ameha NeuralMicrosoft ships two documented Amharic neural voices.am-ET-AmehaNeuralam-ET-AmehaNeuralDocumented language support
Azure Mekdes Neuralam-ET-MekdesNeuralam-ET-MekdesNeuralDocumented language support
Gemini 3.1 Flash TTSPublic preview. Google documents Amharic support for Gemini-TTS.gemini-3.1-flash-tts-previewKoreDocumented language support
OpenAI gpt-4o-mini-ttsgpt-4o-mini-ttscoralUnsupported language condition
ElevenLabs v3ElevenLabs documents Amharic for transcription, not for synthesis.eleven_v321m00Tcm4TlvDq8ikWAMUnsupported language condition
Meta MMSfacebook/mms-tts-amhsingle-speakerOpen research model
Human reference recordingThe original recording each prompt was taken from. Field audio with variable level and microphone quality, included as a reference point for the listening axes.Original dataset audioDataset speakersHuman recording

Addis Voice 2 in this run is the production standard checkpoint, with reference voice am-yohanes-calm.

Protocol

Dataset, splits and scoring rules

The prompts are public test-split rows from three open datasets, pinned to exact repository revisions. Nothing was written for this benchmark, nothing was hand picked, and the selection was drawn once with a fixed seed.

SourceRepositorySplitLicenceRowsPinned revision
FLEURSgoogle/fleurstestCC BY 4.03470bb2e84b976b7e960aa89f1c648e09c59f894dd
Waxalgoogle/WaxalNLPtestCC BY-SA 4.033e91442a8989b291485cb6f8a56c0a8743d36036a
Horn-ASRLesanAI/Horn-ASRtestCC BY-SA 4.033a2a8ab2f09e715256a1b43db572d6abedd1a8129

Length strata

  • Short33 prompts
  • Medium34 prompts
  • Long33 prompts

Balanced on purpose. Short prompts give a recogniser almost no context to recover from an error, and long prompts are where repetition and truncation failures appear.

Judge

  • RecogniserChirp 3
  • Judge audio16 kHz mono PCM WAV
  • Amharic rows scored800 of 800

WER/CER was measured with Chirp 3, a third-party recogniser, so that no system in this benchmark is scored by its own vendor. The pipeline is recogniser-agnostic and can be re-run with Addis AI STT or our open Amharic models; across the recognisers we tested the ordering held, so the scores track the audio rather than the judge. Read them as a recognition-based proxy for intelligibility.

Scoring

  • AggregationMicro-averaged edit counts
  • IntervalsUtterance bootstrap, 95%
  • VerificationIndependent Levenshtein re-run

Text is Unicode normalised, punctuation is stripped, equivalent Amharic characters are folded, and whitespace is collapsed before the edit distance is taken. CER is measured over the normalised text with spaces removed; WER over whitespace-split tokens.

Result 1

Intelligibility by recognition error

Lower is better. Each row is the same 87 prompts put through the same judge. Confidence intervals are deterministic utterance-bootstrap intervals at 95%. Confidence intervals show uncertainty around each estimate; overlapping intervals should be interpreted cautiously.

Primary CER/WER uses 87 non-numeric prompts to avoid digit and spoken-form normalisation ambiguity. The full 100-prompt scores are shown separately in the strict full set column.

Character error rate

Amharic, 87 prompts, lower is better

0%10%20%30%40%Gemini 3.1 FlashGemini 3.1 Flash: 2.89% (95% CI 2.17 to 3.73)2.89%Azure AmehaAzure Ameha: 3.03% (95% CI 2.25 to 3.88)3.03%Azure MekdesAzure Mekdes: 4.15% (95% CI 3.11 to 5.16)4.15%Addis Voice 2Addis Voice 2: 4.44% (95% CI 3.46 to 5.54)4.44%Meta MMSMeta MMS: 7.86% (95% CI 6.71 to 9.19)7.86%gpt-4o-mini-ttsgpt-4o-mini-tts: 18.74% (95% CI 13.31 to 25.23)18.74%ElevenLabs v3ElevenLabs v3: 111.65% (95% CI 98.55 to 128.99)111.65%Character error rate, percent
Addis Voice 2Other systems
Whiskers are the 95% bootstrap interval. The confidence intervals overlap substantially, so the point-estimate ordering among the top four should be interpreted cautiously. The ElevenLabs bar runs past the axis and is torn off at the edge with its true value printed inside, so one outlier does not flatten every difference that matters.

Word error rate

Amharic, 87 prompts, lower is better

0%10%20%30%40%Gemini 3.1 FlashGemini 3.1 Flash: 11.02% (95% CI 8.94 to 13.27)11.02%Azure AmehaAzure Ameha: 11.16% (95% CI 9.08 to 13.27)11.16%Azure MekdesAzure Mekdes: 13.01% (95% CI 10.78 to 15.29)13.01%Addis Voice 2Addis Voice 2: 13.87% (95% CI 11.57 to 16.21)13.87%Meta MMSMeta MMS: 22.89% (95% CI 20.27 to 25.55)22.89%gpt-4o-mini-ttsgpt-4o-mini-tts: 31.34% (95% CI 26.06 to 37.02)31.34%ElevenLabs v3ElevenLabs v3: 147.86% (95% CI 130.97 to 168.92)147.86%Word error rate, percent
Addis Voice 2Other systems
Word error rate above 100% is not a rendering fault. A system that inserts more words than the reference contains can exceed 100%, which is what fluent audio in the wrong phonology produces.
SystemnCER95% CIWER95% CIStrict full set CER / WER
Gemini 3.1 Flash TTS872.89%2.17 – 3.7311.02%8.94 – 13.273.90% / 12.48%
Azure Ameha Neural873.03%2.25 – 3.8811.16%9.08 – 13.274.18% / 12.93%
Azure Mekdes Neural874.15%3.11 – 5.1613.01%10.78 – 15.295.37% / 14.94%
Addis Voice 2874.44%3.46 – 5.5413.87%11.57 – 16.215.76% / 15.80%
Meta MMS877.86%6.71 – 9.1922.89%20.27 – 25.558.97% / 24.96%
OpenAI gpt-4o-mini-tts8718.74%13.31 – 25.2331.34%26.06 – 37.0219.07% / 31.77%
ElevenLabs v387111.65%98.55 – 128.99147.86%130.97 – 168.92112.72% / 148.81%

Addis Voice 2 by prompt length

Amharic, lower is better

0%5%10%15%20%25%Short promptsShort prompts — CER: 8.068.06Short prompts — WER: 18.7518.75Medium promptsMedium prompts — CER: 5.475.47Medium prompts — WER: 14.7914.79Long promptsLong prompts — CER: 5.145.14Long prompts — WER: 15.3615.36Error rate, percent
CERWER
Short prompts are our weakest slice. With less context a single mis-rendered syllable moves the score a long way, and the pattern is consistent across both metrics.

Addis Voice 2 by dataset source

Amharic, lower is better

0%5%10%15%20%25%FLEURSFLEURS — CER: 6.716.71FLEURS — WER: 16.6116.61Horn-ASRHorn-ASR — CER: 7.477.47Horn-ASR — WER: 19.0319.03WaxalWaxal — CER: 3.423.42Waxal — WER: 11.7811.78Error rate, percent
CERWER
Waxal is our strongest source and Horn-ASR our weakest. The human recordings show the same ordering reversed, which is a sign that recording domain, not model behaviour, drives part of this spread.

Addis Voice 2 by slice

By sourcenCERWER
FLEURS346.71%16.61%
Horn-ASR337.47%19.03%
Waxal333.42%11.78%
By lengthnCERWER
Short338.06%18.75%
Medium345.47%14.79%
Long335.14%15.36%
Held out of the primary tablenCERWER
Numeric prompts1314.94%28.18%

The arithmetic behind the headline numbers

SliceRowsCharacter errors / reference charactersCERWord errors / reference wordsWER
Primary, digits excluded87362 / 8,1524.44%292 / 2,10613.87%
Strict full set100537 / 9,3235.76%385 / 2,43615.80%
Numeric prompts only13175 / 1,17114.94%93 / 33028.18%

Percentages are micro-averages of raw edit counts, not the mean of per-utterance percentages. The two differ, and publishing the counts lets you check which one we used.

Result 2

Blind listening evaluation

Every clip was rated by native Amharic speakers on naturalness, intelligibility and voice quality on a 1 to 5 scale. Provider identities were hidden behind rotating labels during evaluation and revealed only after scoring was complete. Composite is the mean of the three axes.

Blind listening scores by axis

Amharic, 100 clips per system, 1 to 5, higher is better

012345Addis Voice 2Addis Voice 2 — Naturalness: 4.014.01Addis Voice 2 — Intelligibility: 4.804.80Addis Voice 2 — Voice quality: 3.943.94Gemini 3.1 FlashGemini 3.1 Flash — Naturalness: 3.903.90Gemini 3.1 Flash — Intelligibility: 3.963.96Gemini 3.1 Flash — Voice quality: 3.673.67Azure AmehaAzure Ameha — Naturalness: 2.542.54Azure Ameha — Intelligibility: 4.494.49Azure Ameha — Voice quality: 3.443.44Meta MMSMeta MMS — Naturalness: 3.093.09Meta MMS — Intelligibility: 2.842.84Meta MMS — Voice quality: 3.173.17gpt-4o-mini-ttsgpt-4o-mini-tts — Naturalness: 1.201.20gpt-4o-mini-tts — Intelligibility: 3.473.47gpt-4o-mini-tts — Voice quality: 2.982.98ElevenLabs v3ElevenLabs v3 — Naturalness: 1.001.00ElevenLabs v3 — Intelligibility: 1.231.23ElevenLabs v3 — Voice quality: 3.773.77Mean rating, 1 to 5
NaturalnessIntelligibilityVoice quality
Naturalness, intelligibility and voice quality are reported separately because systems can score very differently across the three axes.
SystemCompositenNaturalnessIntelligibilityVoice quality
Addis Voice 24.251004.014.803.94
Gemini 3.1 Flash TTS3.841003.903.963.67
Azure Ameha Neural3.491002.544.493.44
Meta MMS3.031003.092.843.17
OpenAI gpt-4o-mini-tts2.551001.203.472.98
ElevenLabs v32.001001.001.233.77
Evidence

Listen to the clips and read the judge transcript

Numbers about speech are only worth what the audio behind them is worth. These are the archived benchmark outputs, unedited, with the exact transcript the recognition judge returned and the score that transcript produced.

How these three prompts were chosen

The lowest-numbered medium-length Amharic prompt from each of the three sources, selected before the audio was reviewed.

Prompt textgoogle/fleurs · row 1797 · CC BY 4.0

ሁሉም ሰው በኅብረተሰብ ውስጥ ይሳተፋል እና የትራንስፖርት ስርዓቶችን ይጠቀማል ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቅሬታ ያቀርባል

Addis Voice 2Addis AI
CER 1.39%WER 5.56%

ሁሉም ሰው በህብረተሰብ ውስጥ ይሳተፋል እና የትራንስፖርት ስርዓቶችን ይጠቀማል ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቅርሬታ ያቀርባል

Human reference recordingReference
CER 2.78%WER 5.56%

ሁሉም ሰው በሕረብተሰብ ውስጥ ይሳተፋል እና የትራንስፖርት ስርዓቶችን ይጠቀማል፣ ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቅሬታ ያቀርባል።

Azure Ameha Neural
CER 1.39%WER 11.11%

ሁሉም ሰው በህብረተሰብ ውስጥ ይሳተፋልና የትራንስፖርት ስርዓቶችን ይጠቀማል ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቅሬታ ያቀርባል

Azure Mekdes Neural
CER 1.39%WER 11.11%

ሁሉም ሰው በህብረተሰብ ውስጥ ይሳተፋልና የትራንስፖርት ስርዓቶችን ይጠቀማል ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቅሬታ ያቀርባል

Gemini 3.1 Flash TTS
CER 1.39%WER 11.11%

ሁሉም ሰው በህብረተሰብ ውስጥ ይሳተፋልና የትራንስፖርት ስርዓቶችን ይጠቀማል። ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቅሬታ ያቀርባል።

OpenAI gpt-4o-mini-tts
CER 0.00%WER 0.00%

ሁሉም ሰው በህብረተሰብ ውስጥ ይሳተፋል እና የትራንስፖርት ስርዓቶችን ይጠቀማል ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቅሬታ ያቀርባል

Meta MMS
CER 2.78%WER 16.67%

ሁሉም ሰው በህብረተሰብ ውስጥ ይሳተፋል እና የጠራን ስፖርት ስርዓቶችን ይጠቀማል ሁሉም ሰው ማለት ይቻላል ስለ መጓጓዣ ስርዓቶች ቀሬታ ያቀርባል

ElevenLabs v3
CER 97.22%WER 161.11%

ሳይሞ ብሪግን አወት ሶአርት ቱዋይ ኢት ኢን ቬካቭ ፓቡ ሳይቭ ዶር ሲንግ ኡን ሱጋ ዲ ቻይ ሳይሞ ፋይቭ ሱጃይ ሴ አማቴቶ ሳይቭ ዶር ሲንግ ኡን ቱል ፊ ዳብ ቻይ

Clips are loudness-normalised to a common level and transcoded to mono 24 kHz MP3 for playback. Scoring ran on canonical 16 kHz mono PCM WAV files. Human reference clips are redistributed under the licence of their source dataset, CC BY 4.0 for FLEURS and CC BY-SA 4.0 for Waxal and Horn-ASR, with attribution in the dataset table above.

Serving

Latency and cost

Every system was measured through its public API from a single location, so these are raw request times. Clip length differs between systems and is not adjusted for: Addis Voice 2 generated 31.25 minutes of audio across the 100 prompts against Azure Ameha Neural's 18.68. The RTF column divides time taken by audio produced and is the like-for-like comparison.

Amharic request latency

p50 with the tail out to p95, lower is better

0s6s12s18s24sAzure MekdesAzure Mekdes — p50: 1.04sAzure Mekdes — p50 to p95: 0.71s1.75sAzure AmehaAzure Ameha — p50: 1.05sAzure Ameha — p50 to p95: 0.82s1.87sgpt-4o-mini-ttsgpt-4o-mini-tts — p50: 3.80sgpt-4o-mini-tts — p50 to p95: 4.44s8.24sAddis Voice 2Addis Voice 2 — p50: 5.40sAddis Voice 2 — p50 to p95: 5.43s10.83sMeta MMSMeta MMS — p50: 7.01sMeta MMS — p50 to p95: 11.43s18.44sGemini 3.1 FlashGemini 3.1 Flash — p50: 8.94sGemini 3.1 Flash — p50 to p95: 8.60s17.54sElevenLabs v3ElevenLabs v3 — p50: 9.97sElevenLabs v3 — p50 to p95: 11.62s21.59sSeconds
p50p50 to p95
The solid segment is p50 and the lighter segment is the tail out to p95.
Systemnp50p95Mean RTFFailuresServing
Addis Voice 21005.401s10.827s0.4440Vendor API
Azure Ameha Neural1001.046s1.871s0.1060Vendor API
Azure Mekdes Neural1001.045s1.752s0.1100Vendor API
OpenAI gpt-4o-mini-tts1003.798s8.238s0.2680Vendor API
Meta MMS1007.014s18.444s0.5760Open weights, run locally
Gemini 3.1 Flash TTS1008.941s17.537s0.7000Vendor API
ElevenLabs v31009.970s21.591s0.8910Vendor API

Cost per provider

ProviderBilling unitRatePer generated audio minuteRecorded in this run
Addis Voice 2Generated audio minuteUSD 0.031 per minuteUSD 0.0309USD 0.96 for 31.25 generated minutes
Azure Ameha NeuralCharacters of inputUSD 15.00 per 1M charactersUSD 0.0095USD 0.18 for 11,889 input characters, 18.68 minutes
Azure Mekdes NeuralCharacters of inputUSD 15.00 per 1M charactersUSD 0.0100USD 0.18 for 11,889 input characters, 17.92 minutes
Gemini 3.1 Flash TTSOutput audio tokensUSD 20.00 per 1M output tokensUSD 0.0300USD 0.69 for 34,695 output tokens, 23.13 minutes
OpenAI gpt-4o-mini-ttsGenerated audio minuteUSD 0.015 per minuteUSD 0.0150USD 0.44 for 29.57 generated minutes
ElevenLabs v3Characters of inputUSD 0.10 per 1,000 charactersUSD 0.0575USD 1.19 for 11,889 input characters, 20.68 minutes
Meta MMSOpen weights, run locallyNo vendor rateNo vendor rate26.50 minutes, infrastructure cost only

Every row covers the same 100 Amharic prompts and is computed from the generated audio and input text of this run. Providers bill in different units, so the columns are not directly comparable. The Gemini figure covers output audio only.

Reproduce

Run this yourself

The prompts, every generated clip, the judge transcripts, the scorer and the checksums are published as an open dataset. Running score.py rebuilds the CER/WER tables and figures from the published judge transcripts.

What the dataset contains

data/prompts.jsonl

100 rows. Source dataset, pinned repository revision, upstream row id, split, licence, reference text, normalised text, length stratum, character count, human audio hash and duration.

data/judge_rows.jsonl

800 rows. System, raw and normalised transcript, character and word edit counts, reference lengths, CER, WER, judge confidence, plus the audio path and SHA-256 of the exact file that produced the row.

audio/

800 clips. One per prompt per system, plus the original human recordings, with a metadata index listing each clip against its transcript, CER and WER.

score.py and checksums.sha256

The scorer, which rebuilds the CER/WER tables and figures from the published judge transcripts with no arguments, and a SHA-256 for every shipped file.

800 judge rows, 800 audio clips, the scorer and a checksum for every file are published at addisai/amharic-tts-benchmark. Questions to contact@addisassistant.com.

Test it on your own text

The clips above are 100 rows of a public dataset. Your workload is not. Run Addis Voice 2 against your own Amharic content and check the result yourself.