Can you whistle while eating crackers?

The answer is no.
I can whistle, not very loud, and definitely not while eating crackers.

Now, Bonnie the orangutan is some whistler!

She's 32 and shows off a low sweet whistle below. Evidently she's the first great ape...or the first we humans know about. Frankly, they are pretty intelligent animals and don't need any fancy tricks to get by. But to please someone, Bonnie got her whisle down. My whistling skills are pitiful in incomparison!

If you want a huge whistle just listen for my sister at one of her nieces'/nephews' graduations. Sit with her at these public celebrations and you'll need earplugs. I don't know how she does it...she just puts two fingers in her mouth and blows.

The kids could hear it as they walked across the stage. And they knew who it was!!
I found an example, of a loud whistle, though not of my sister's calliber, but loud nonetheless:

Wow that's a whistle!