In the Voxtral paper's Table 3, GPT-4o mini Transcribe had a word error rate of 17.31 percent on Switchboard.

Quote found word for word on the live source, last checked October 19, 2026

In the source's own words

“Model LS-C LS-O GS VP SB C-4 SPGI E21 10m E22 10m ... GPT4o mini Transcribe 1.92 4.70 14.80 7.34 17.31 11.35 4.51 10.09 12.27”

Voxtral, Mistral AI, arXiv (Audio and Speech Processing), 2025, Table 3 (short-form English), Switchboard column.

What it measures: Table 3 of the paper gives word error rate for each English test set. The paper calls the Voxtral results macro-averages in its figures, and this row is one test set.
What it does not show: One paper's runs under its own text normalization and decoding, so compare systems within this table, not with other papers' numbers. The paper gives no date per row.

A row of Speech Recognition Accuracy: Word Error Rates, as GPT-4o mini Transcribe, Switchboard: 17.31 percent.