You are at a party, and Alex is telling a boring story. You are much more interested in the gossip that Sam is recounting to Pat, so you tune out Alex and focus on Sam’s words. Congratulations: you have just demonstrated the human ability to solve the “cocktail party problem”—to pick out one thread of speech from the babble of two or more people. Computers so far lack that power.
Although automated speech recognition is increasingly routine, it fails when faced with two people talking at once. Computerized speech separation would not only improve speech-recognition systems, it could also advance many other endeavors that require the separating of signals, such as making sense of brain-scan images.