Me: If humans lose the ability to hear high frequency volumes as they get older, can my 4 week old son hear a dog whistle?

Doctor: No, humans can never hear that high of a frequency no matter what age they are.

Me: Trick question... dogs can't whistle.

What if they can and we can't hear it?

@HitWRight My guess is the reason dogs sense things from us and other people who think they are being quiet. It is because they can hear those frequencies. Like a dog can detect epileptic seizures before they happen. Is it smell, is it sound, is it a combination?

Also, if you get a transducer and divide the freq down you can hear freq dogs can. It is common to do this to hear bats.

@HitWRight
Of course they can!
But as dogs are an inherently subtle species, their whistling is called barking...