She is feverish and just wants grandpa but she doesn't want him to talk. When he talks she pats his chest, says "heart" and presses her ear tighter. The sound must be comforting. she meant that she was listening to his heart for sure, and anything that interrupted that was not to be tolerated. Once ibuprofen kicked in he was allowed to sing, but only "baby beluga"
I hope she feels better soon.