From the way you asked your question, you are not a complete stranger to SpanishDict.com.
I want you to "click" on the Dictionary Tab on the right hand side toward the top of this page.
In the little window where you can enter words, enter the verb "Escuchar".
When the definition for "escuchar" shows on your screen, you will see that the word means "to listen to".
The reason you do not need to write "escuchaba a" is that you would be writing "was listening to to " or to say that another way, you would be repeating "to" twice.
Now, go back to the dictionary and enter the verb "Hacer".
The first line of that definition explains that "hacer" means "to do (realizar) (estudios, experimento, favor); to make (viaje, sacrificio, promesa); to take (comunión); to ask (pregunta)".
To answer your 2nd question, "hacer is used because it means "to ask".
I suppose at some level you could say it means "he wasn't making a question", but that is the same anyway as to say "He wasn't asking a question".
Oh My! I have to get a lot faster writing up replies. Once this was posted, I saw that Qfreed and Lazarus1907 had already sent you good replies. My answer is simply repetitious. Sorry for the excess.