An article in Medical News Today discusses new research from scientists at the University of Oregon's Institute of Neuroscience about the way sounds are processed. There seem to be two pathways, one which processes the beginning of sounds, and the other, which processes the end of sounds. They both come together in the auditory cortex. Research into this could lead to the development of new hearing devices that would address the problem depending on which part of speech a person is having trouble hearing.
According to Dr. Wehr, one of the authors of the study, "'We think that we've discovered brain mechanisms that are important in finding the necessary boundaries between words that help to allow for successful speech recognition and hearing.'" This research could lead to strategies and devices to help people differentiate competing voices or differentiate a voice from background music or noise.
Like many other people with hearing loss, a loud room with a lot of sound going on at once is not an ideal situation for me to hear one particular voice. Not only do sounds run together but I'm not liable to catch when someone starts speaking and miss half the words they're saying. This is a pretty cool study. I hope some concrete help comes out of it.