Hi, When I try to go walking near my home I am regularly faced with dogs barking at me and sometimes even chasing me. I have heard that there is a small handheld device available that, when activated, emits a high pitched noise (inaudible by humans) that scares away dogs. I have heard that some Co. council employees are supplied with them but not sure if this is true. If this device does exist, does anyone know where I can buy one and also roughly how much it will cost?