Ultrasonic Anti-bark

 It functions in a similar fashion to an ultrasound collar, but works on a greater scope and thus can be used to train/correct dog/s in a wide area. The device which is installed nearby the area inhabited by the target/s, detects barking and emits a sound, unpleasant to a dog but impossible to be heard by a human. After several repetitions, most of dogs realize that their barking is the trigger to the unpleasant sound and hence will not stop barking.