Will I be able to hear on my cell phone or land line better?
Provided your cell phone, or land line produces a decent sound signal to start with. Yes, absolutely. However, even the best hearing instruments only reproduce the sounds that go into them clearly, and without distortion. If, there is an already distorted signal being produced by the cell phone, or land line, it will only be a louder, distorted signal coming out. Hearing aids can’t change garbage into gold, any more than a computer can.
The old adage still stands, garbage in, garbage out.
This applies equally to understanding the Television. Some of today’s TVs have great pictures, but very poor sound quality. If, there is a poor quality audio signal to start with, no hearing aid can change that.