A patient who is completely deaf in his right ear, he still can hear from that side. A sound processor he wears just behind his right ear converts sound waves into tiny vibrations that move through his skull. The vibrations are detected by his good left ear, so it sounds to him like he can hear from both sides. A new study has found that this system of conducting sound through skull bone is a big boost to people who are deaf in one ear and can’t be helped by hearing aids or cochlear implants.