I used to walk home from school past a neighbour who had a similar system. The speakers were quite pathetic, so we figured out it was a recording pretty quickl

I used to walk home from school past a neighbour who had a similar system. The speakers were quite pathetic, so we figured out it was a recording pretty quickly. And so we took to running past the house again and again, triggering the barking noise to our delight. A few weeks later, the system was removed.