This is the 13227th most frequent German word.
aufhorchen
"Aufhorchen" means "to perk up one's ears" or "to listen attentively."
The verb 'aufhorchen' is used to describe attentively listening or reacting to something unexpected.
Die Kinder hörchen auf, als die Lehrerin zu sprechen begann.
The children perked up when the teacher began to speak.
Here, 'aufhorchen' conveys the act of paying attention due to sudden interest.
Er hörchte auf, sobald er das unbekannte Geräusch hörte.
He pricked up his ears as soon as he heard the unfamiliar sound.
In this context, 'aufhorchen' is used to signify that someone's interest was suddenly caught by an external stimulus.