Howling is a way that dogs communicate with you or other dogs. Dogs howl because of pain, loneliness, or hearing a provocative sound. A common trigger for a dog to howl is a fire truck siren, police car or other harsh sound. If the dog's howling is frequent and annoying, then you can train the dog to become numb to the sound.
When rushing to put out a fire, fire engines emit a very loud, wailing siren, similar to the way an ambulance honks to get drivers and pedestrians out of the way. From a distance, it sounded a lot like a dog's wail. According to "Dogs: The Ultimate Care Guide: Healthy, Loving, and Most Alive," the dog thought it might be another dog saying hello, curious that he would growl in response to the "dog," which was actually an alarm. "Growling is often a form of communication between dogs over long distances, so the dog will think it's another dog, in a far away place, talking to him."
Dogs can hear high-pitched responses up to 45 Hertz and the sound of a fire truck siren is a loud, high-pitched pitch, and dogs can hear it even higher. Based on the Doppler effect, your dog thinks the siren is sounding higher when a moving fire truck approaches his location; As it drove away, the siren sounded quieter. According to Louisiana State University, dogs can hear high pitched voices up to 45 Hertz, while humans can only hear 23 Hertz. With superhuman hearing, some dogs howl out of frustration at an annoying siren that contains high-frequency tones you can't hear. The dog may even find that his roar can stop it - in fact, the fire truck just drives away.
Use howling to alert the owner to the sound of a fire truck siren, and the dog may alert you to the presence of this strange, loud sound by howling. If you try to calm him when he yells at a passing siren, you inadvertently reinforce his behavior in responding to the siren. According to the Central News Agency, any type of attention you give, even negative attention like yelling to quiet the puppy, sends a message to your dog that if he yells his siren, you will pay attention. If he's howling to get your attention, then you can ignore him completely when he's howling alarm and maybe stop the behavior.