Fact · Speech recognition
15.45percent word error rate
In our October 2026 test on a Mac with an M2 Pro, Apple SpeechTranscriber had a word error rate of 15.45 percent on 97 conversational utterances by speakers of Mainstream US English (9 speakers) from the EdAcc corpus.
Measured by us on October 21, 2026, from 97 recordings
Our own measurement
This number comes from our benchmark, not from another publication. The full record (the setup, every recording's checksum, every transcript and timing) is published, so you can recompute it.
- What it measures
- Apple's on-device speech model in macOS 26 (SpeechAnalyzer with a SpeechTranscriber module, transcription preset), with the locale given (en-US, de-DE, fr-FR, es-MX, it-IT, pt-BR). The recordings are English conversations over video calls between people with different accents (EdAcc, University of Edinburgh, 2023), not read sentences, so error rates run higher than on our read-speech benchmark. The utterances were picked by a fixed rule before any engine ran: at least five words, 1.5 to 30 seconds, no overlapping speech, up to 100 per accent group spread across its speakers.
- How it is measured
- Word error rate = 345 word errors / 2,233 reference words = 15.45 percent, over 97 utterances; hesitation fillers are left out of both texts and ok counts as okay, for every engine alike.
- What it does not show
- 9 speakers stand for this group, so one speaker's voice, microphone and topic weigh heavily: compare engines within a group more than groups with each other. Numbers spoken as words in the reference count as errors when an engine writes digits.
In the data
A row of Speech Recognition and Accents: 13 English Accents Tested, as Apple SpeechTranscriber, Mainstream US English: 15.45 percent.
- Engine
- Apple SpeechTranscriber
- Maker
- Apple
- Accent group
- Mainstream US English
- Kind of accent
- Variety of English
- Speakers
- 9
- Utterances
- 97
Used to calculate
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