Place this clip right after the confusing quote in your edit, then follow it with a funny ha ha laugh once the reaction settles, or precede it with a yeah reaction when someone confidently says the line that sets the confusion up.
O tym dźwięku
This clip is a stretched vocal call lasting just under six seconds, with the words drawn out in long, wobbling vowels that keep rising as if the speaker cannot believe what he heard. It feels bewildered and playful, turning simple confusion into an exaggerated reaction that listeners instantly read as disbelief mixed with amusement.