[Bailey_]

American bulldogs tend to be a very protective, and territorial breed. They naturally want to keep their home safe from intruders.

When dogs bark at something outside, it's a GOOD thing. It just means that she is warning her people that there is something outside; even if it can be very disturbing and annoying for us humans.

How old is she?

It's great that you've been trying to work with her and figure out how to train her through this, but unfortunatley sometimes when we try EVERY!METHOD! we end up showing a lot of inconsistancy to our dogs, which in turn shows weakness.

Consistancy is your best option. Training a dog out of a certain behavior often times doesn't just happen overnight, over a few days, weeks, or months.

You mentioned that it happens outside...could you elaborate?

In the house, try to pick a spot - her bed, kennel, whatever. Has she mastered the sit/stay? If so, when you are in the house with her and she barks, tell her 'thankyou' and ask her to sit or lie down in the spot you've designated for her. Innterupting the barking by physically redirecting her brain from the noises, acknowledging the fact that you are aware there is a sound but asking her to do something for you - will be a good way to start showing her that when you are home, you are in charge. She can relax, and one or two barks to let you know she heard something is absolutley fine.

I personally don't like the thought of training a dog NOT to bark. We have to keep in mind that barking is our dogs way of communicating vocally to us. If there was ever an instant (like an intruder) where we wanted them to alert us of something, chances are if she was wearing a shock collar - she wouldn't.