Yes, she can still benefit. If you listen carefully to just one ear, you will hear in the background what is primarily in the other ear. Everything comes through.
Paul says that if you are going to be deaf in one ear, the best is the right ear, because Paraliminals work best going into the left.
Depending on her deafness, she should still use stereo headphones, because the vibrations from the right speaker can still be picked up and processed by the brain.
