To improve hearing acuity do the following-start to humm, once the humming is going open your mouth and continue the sound,then consciously move the sound up to the ear you have hearing problems with-keep the open mouthed hummm going and make it louder, if a problem in both ears move the sound from one ear to the other. You may be saying that this is impossible but you can really do this. When I practice the humming with the mouth open,(a totally different sound) the longer the better, my husband notices that I do not need the T.V. up as loud. The activity apparently stimulates the nerves in the ears. I read about this natural anecdote to hearing problems years ago. Of course it would depend on the nature of your hearing loss but it is worth a try and you must keep it up every day to retain the advantage.