Astonishing new results from an invasive brain-computer interface for restoring text entry and speech output for users who are unable to move or speak due to motor impairments. Willet et al. (2023) showed in a paper on BioRxiv that a speech output rate of 60+ words per minute was achieved by decoding single-neuron-level signals from the left BA6v (premotor cortex) and BA44 (part of Broca's area) using a RNN, in a single individual with ALS. Word error rate analyses are also found in the paper.

https://www.biorxiv.org/content/10.1101/2023.01.21.524489v1.full.pdf