Native Japanese context test
Can AI Understand Japanese Homophones?
We put eight everyday words into one natural Japanese recording. Notta, Sonix, and TurboScribe all produced readable transcripts—and all chose some convincing but incorrect kanji.
We wrote and recorded the Japanese source, sent the same file to every tool, and checked each target word manually. Notta and Sonix links are affiliate links. We may earn a commission after a qualifying purchase, at no extra cost to you. This does not affect our scores.
Eight words that sound alike in three groups
The task was not merely to hear the pronunciation. Each tool had to use the surrounding sentence to choose the intended kanji and meaning.
変える・替える・換える
kaeruchange a setting · replace a battery · exchange the air
撮る・取る・採る
torutake a photo · collect a survey · hire staff
贈る・送る
okurugive a gift · send an email
One natural 34.75-second recording made in Japan
The script described changing an air-conditioner setting, replacing a battery, ventilating a room, taking a product photo, collecting a survey, hiring three staff members, giving a wedding gift, and sending an email.
Notta and Sonix tied at 5/8
We scored only the eight target words. The intended kanji counted as correct; a different kanji was wrong. A hiragana rendering would have been marked unresolved, although none of these three outputs used hiragana for the target words.
| Tool | Score | Missed targets | What we observed |
|---|---|---|---|
| Notta | 5/8 | 替える, 換える, 採る | Changed both replace/exchange verbs to 変える and wrote 撮る (photograph) for hiring. |
| Sonix | 5/8 | 替える, 換える, 採る | Made the same two 変える substitutions and wrote 取る (take) for hiring. |
| TurboScribe | 4/8 | 替える, 換える, 採る, 贈る | Also lost the gift meaning, writing 送る for both the gift and the email. |
WHAT WORKED
- All three correctly transcribed changing the temperature, taking a photo, collecting a survey, and sending an email.
- Notta and Sonix correctly used 贈る for giving the wedding gift.
SHARED FAILURES
- All three changed 替える and 換える to the more general 変える.
- All three failed to use 採る for hiring staff.
Product details: Notta review, Sonix review, and TurboScribe review.
We strengthened the context before scoring the test
An earlier pilot was rejected because one line was misread and the phrase about hiring staff was too isolated. We recorded a clean second version with a labor shortage, a new store, and a specific plan to hire three staff members. Only that second recording appears in the results above.
結婚祝いの品を友達に贈る→ give a wedding gift to a friend
Notta and Sonix correctly separated 贈る for the gift from 送る for the later email. TurboScribe used 送るfor both actions.
スタッフを三人採る予定です→ plan to hire three staff
Notta wrote 撮る—to photograph—while Sonix and TurboScribe wrote 取る—to take. All are pronounced toru, but only 採る expresses hiring in this sentence.
The wrong kanji can look completely normal
A non-Japanese reader may not notice these errors because the outputs are valid words and the sentences still look polished. But “hire three staff” becoming “photograph three staff” changes the real-world instruction.
Sonix also labeled 91.76% of words in its transcript as “very confident,” while our native check still found three wrong target kanji. That confidence display is not the same as a native-reviewed accuracy score.
Use a free allowance, then check meaning—not just readability.
Sonix offers 100 free transcription minutes through our invitation link.
Affiliate disclosure: we may earn a commission if you make a qualifying Notta or Sonix purchase through our links, at no extra cost to you. Our scores are based on the observed transcripts above.
How we kept the comparison fair
- 1One source file.
All three completed services received the same M4A recording.
- 2Native reference script.
We compared each target with the intended word in the final spoken script.
- 3Target-word scoring.
We did not inflate the result with easy surrounding words.
- 4Rejected pilot excluded.
The first take was not ranked because it did not provide a fair enough prompt.
- 5Narrow conclusion.
One voice, room, script, and product version cannot establish a universal winner.
Compare these tools across our broader Japanese benchmark.
Numbers, names, corrections, speakers, noise, and business codes included.
Japanese homophone transcription FAQ
Can AI transcription choose the correct kanji for Japanese homophones?
Sometimes, but not reliably in every context. In this recording, Notta and Sonix each selected 5 of 8 target words correctly, while TurboScribe selected 4 of 8. All three failed the battery, ventilation, and hiring targets.
Which tool was best in this Japanese homophone test?
Notta and Sonix tied at 5/8 in this one targeted test. That is not a universal ranking: our broader comparison also checks numbers, names, corrections, speakers, noise, and business identifiers.
Did more sentence context improve the transcription?
It helped in one clear case. Notta and Sonix distinguished 贈る for giving a wedding gift from 送る for sending an email. However, all three tools still missed 採る even after the sentence mentioned a labor shortage, a new store, and three staff members.
Why was Otter.ai not included?
We could not import this additional recording within the account allowance used for testing. That is a test-coverage limitation, not evidence about Otter.ai's accuracy.