The CatScram electronic pet repellent device is motion activated. As a result, and the CatScram electronic pet repellent device will be triggered by any motions.
Even when active a human will not be able to detect the sound emitted by the CatScram.
No harm will be done by intermittent exposure and your cat will soon learn to avoid the entire affected area. However, if the cat were confined to the affected area a number of maladies could occur including hearing loss, aggressive behavior, and other psychological problems.