If you were as blind as a bat, then you would will be much better off at tectin than if you were stone deaf. If you cant hear good, you aint gonna tect good. Screens wont help. At all. Unless you are in a spot where there is very little trash, and very much treasure. So what I am saying is that the tecter has to have good loud volume. Headphones and audio trump screens and numbers. I recommend any machine that has a good enough audio driver to make everything louder than hell at max volume, and use good quality full headphones, the ones that cover your ears. My cz is louder than most because its an underwater unit, I have to run my volume in low range with it. The best thing to do is to get good hearing aids, quality ones, the ones that cost more than metal detectors. Then its all good.