Extended Data Fig. 6. Phoneme substitution errors observed across all real-time evaluation sentences.

Entry (i.j) in the matrix represents the substitution count observed for true phoneme i and decoded phoneme j. Substitutions were identified using an edit distance algorithm that determines the minimum number of insertions, deletions, and substitutions required to make the decoded phoneme sequence match the true phoneme sequence. Most substitutions appear to occur between phonemes that are articulated similarly.