- ’Can you speak a bit louder? I can’t hear you.’
- Suddenly she heard a strange noise.
Listen (to) is used to talk about paying attention to sounds one hears. It emphasizes the idea of concentrating. Note that you can hear something without wanting to, but you can only listen to something deliberately.
- I heard them talking in the next room, but I didn’t really listen to what they were saying.
Note that listen to is mostly used to talk about experiences that are going on, in progress.
- When she arrived, I was listening to the radio. (NOT —I was hearing the radio.)
To talk about experiencing the whole of a performance, speech, piece of music or broadcast, we generally use hear.
- Did you hear the news yesterday?
Listen and listen to
When there is no object, listen is used.
- Listen! (NOT Listen to!)
- Listen to me! (NOT Listen me!)