Study that through surgery enhanced the ability of epileptic patients to pick voices out in a noisy crowd:
Obviously, won’t be very practical unless a non-surgical approach can be devised.
Readable Popular Account:
Original Research Paper:
Selection of Other Articles Listed in Google News Covering Same:
Edit_Update: The gist of what a normal brain does to enhance a particular voice that current external HA’s cannot do and what the implant in epilectic patients undergoing surgery attempts to mimic (quoted from StatNews article-1st link)
" Mesgarani started his mining in the brain. He and his graduate adviser discovered in 2012 that when people converse, the listener’s brain waves echo the acoustic features of the speaker’s voice, turning up its perceived volume and filtering out extraneous voices.
That ability comes from the brain’s secondary auditory cortexes, one behind each ear. They amplify one voice over others by the simple means of paying attention, in a process called top-down control. (“Top” means an executive function such as conscious attention; “down” means a sensory function, in this case hearing.) The sound of a familiar voice, a familiar word (one’s name), an emotionally resonant word ( divorce ) or tone, or other attention-grabber causes this region to increase the perceived volume of what grabs its attention.
The brain-controlled hearing aid first separates the audio signals of different speakers. It then determines the spectrogram, or voiceprint, of each, meaning how a voice’s volume and frequency vary with time. Next, it detects the brain waves in a listener’s auditory cortex (via an implanted 16-by-16 electrode array), which indicate what voice the listener is paying attention to. Finally, the system searches for that particular voice and amplifies it, and only it. When the listener’s attention turns to a different voice, the system quiets the first one and dials up the volume on the new one."