Hear is a stative verb (non action), you hear because you have the ability to hear.  Listen is an action verb and requires attention and purpose. So, you hear noise outside, and you hear the birds in the morning, whether you want to or not, but you listen to music or the conversation. 

hola Diego,

te contesto en español si no te molesta :)

"hear" se usa como "oír"

por ejemplo: I hear a noise (oigo un ruido)

"listen to" se refiere a la acción de escuchar

por ejemplo:Silence please, I am listening to the radio

Everything clear now ! :) Thanks a lot ! - Muchas graciaas ! :))