Hello, Tien. Thank you for your question about what is the difference between hear and listen.
We use hear for sounds that come to our ears, without us necessarily trying to hear them! For example, 'They heard a strange noise in the middle of the night.'
Listen is used to describe paying attention to sounds that are going on. For example, 'Last night, I listened to my new Mariah Carey CD.'
So, you can hear something without wanting to, but you can only listen to something intentionally. An imaginary conversation between a couple might go:
'Did you hear what I just said?'
'No, sorry, darling, I wasn't listening.'