Here's why:
* Transitive: It means the action of listening is directed towards something.
* Example: "She listened to the music." (The music is the direct object.)
* Intransitive: It means the action of listening is simply occurring, without a specific object.
* Example: "He listened carefully." (There's no direct object, just the action of listening.)
So, whether "listened" is transitive or intransitive depends on the context of the sentence.