How do you stop it?

My dog is only 7 months and my famiily and I are trying to train her early so she is behaving when she is older and can do a lot more damage to things. We’ve been training her for 5 months and she still keeps biting. I saw this dog show where whenever she bit, you made a sound that a dog would make in pain. It worked for awhile, but then she just ignored it. We stopped because we were afraid that when she hurt another dog, she would think nothing of it. We need better ways to fix her biting issue. Please help.