Why does my dog bring in a crying resonance sometimes when he yawns?

Sometimes when my dog yawns he makes a crying noise as he is yawning. I know he isn't in discomfort or anything but im just Curious why he does that and if other dogs do it?
i really don't know but my dog does it all the time. Its normal. Sometimes even we do it too!
I think that's without fault normal. You might wanna learn also other aspects of dogs' behavior. Take a look at this, http://dogtime.com/behavior.html
Answers:    Totally normal buddy! My little Dewey-dog does it too...

Here's an article that covers a study that be done abut dogs and yawning, it even mentions the little noise you noticed!

http://www.dailymail.co.uk/sciencetech/a...
Ya dogs do that sometimes.. I have read somewhere that dogs even dream.
yeah its normal. adjectives dogs do it. people even do it. when u are really tired. there is nothing wrong next to him tho.
My dogs do it too, it sounds more close to a squeak than a cry. It's normal
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