Ah wah wah. It can have several meanings.
Like the sound in my head after this exchange today:
Henry: (Silly faces, rolling eyes)
Me: It is not nice to roll your eyes.
Henry: (rolling eyes) But mama, what about this? I’m not rolling my eyes. Me: It looks like you’re rolling your eyes…
Henry: No, I’m just looking UP!
And here’s a more literal Ah wah wah. It’s a little slobbery, but somebody has to do it: