Brain-machine interfaces for real-time speech synthesis.

[locked-in syndrome]

This paper reports on studies involving brain -machine interfaces (BMIs ) that provide near-instantaneous audio feedback from a speech synthesizer to the BMI user . In one study , neural signals recorded by an intracranial electrode implanted in a speech -related region of the left precentral gyrus of a human volunteer suffering from locked-in syndrome were transmitted wirelessly across the scalp and used to drive a formant synthesizer , allowing the user to produce vowels . In a second , pilot study , a neurologically normal user was able to drive the formant synthesizer with imagined movements detected using electroencephalography . Our results support the feasibility of neural prostheses that have the potential to provide near-conversational synthetic speech for individuals with severely impaired speech output .