What is the direct object?

Hola Anthony 

Both "Lo escuchamos" and "Le escuchamos" are considered correct. The verb "escuchar" (as in escuchar algo or escuchar a alguien) is a transitive verb with a direct object, or direct object pronoun, which should be lo, la, los, las; however, there is something called leísmo in Spanish that is basically using le/les as direct object pronouns instead of indirect object pronouns. Some cases are incorrect but in this case, referring to a singular male direct object, the RAE says that it is accepted. Here is some information about leísmo. Theres also something called loísmo and laísmo; you'll find links at the end of that short article.

If you want a challenge, here's the whole article by RAE (in Spanish) about leísmo. 

Un saludo cordial.

Inma