Why do dogs howl at sirens??

I do know that dogs here a higher frequency that we can not hear...I also know that they hear quite a bit better than we do...the frequency we hear from the sirens is low enough that we can hear it but I wonder if they also emit the higher frequency we can not hear. Just because a dog doesn't shake his head and run in the dog house does not mean it is not unpleasant to the dogs ears...

about a month ago I ordered a devise that has 2 different frequencies that breaks the dogs from barking...one frequency we can hear but the other is higher so that we as humans can not hear it but the dogs can...well the dogs looked normal to me but they quit barking after a few days but I have quit using it because the 9 volt battery runs out pretty quick...I am in the process of converting it to a 12 volt and will add a solar panel to keep the battery charged...I will post the results I see in the dogs as well as the reliability of the dog bark eliminator as soon as I see the results...