There was a long silence. Harry was thinking of the way Crouch's eyes had bulged as he'd looked down at his disobedient house-elf back in the wood at the Quidditch World Cup.
As an English learner, unclear word meanings are a challenge. A lot depends on the situation and on the relationship between speaker and listener. So, don't be shy!
And so, if you're getting it wrong, if you're getting the song wrong or the intonation wrong, just like the birds, it can lead to real confusion or a breakdown in terms of communication.