On most hearing aid wearer’s wish list is the ability to remove background noise. Whilst that would seem to be utopian, a world without background noise would be a very strange place: the sounds around us connect us to our environment and often alert us to danger.
Claims of reducing or removing background noise in hearing devices have to be taken with a pinch of salt. Background noise is there, everyone with normal hearing hears it all the time; what is important is having the ability to hear above the noise comfortably.
Modern hearing devices sample the incoming sound signal and have the ability to determine what is a single voice, surrounding speech noise (in a crowd) and other background noises. Using this information they can clean up the signal and enhance only the speech which is closest to you.
Speech Extraction does not remove or reduce the noise, but it allows you to comfortably hear speech in a noisy situation by lifting the individual voices above the noise.