In the Rule of St Benedict we find:
Obsculta, o fili, præcepta magistri,
https://www.thelatinlibrary.com/benedict.html
We also have this in some prayers: Exaudī nos Domine sancte, Pater omnipotens, aeterne Deus...
What is the difference between Obsculta and Exaudi?
First, to get this out of the way, obscultare is a variant of auscultare, which is the form you will find in most dictionaries. Exaudire, on the other hand, is a member of the audire family of words.
The difference, roughly speaking, is that auscultare means to listen attentively, believingly, or even obediently. It tends to imply a certain effort on part of the listener; it is also used for eavesdroppers and servants waiting on someone. Here is what Forcellini has to say:
Saepe plus est quam audire: significat enim non solum auribus accipere, sed etiam fidem habere dictis alicujus, eique aliquid praecipienti aut monenti obtemperare, obsequi
Exaudire – which differs from simple audire, insofar as it does differ from it at all, in that it means “to hear from afar, to hear loud and clear” – does not have such connotations. Like English “hear,” it can mean to heed, to grant (in particular vota and preces, which already in classical Latin belies a certain religious tendency). Indeed, it can even mean to obey, although that's somewhat unusual.
Thus, in English terms you could translate St. Benedict as saying: “Listen closely, son, to the teacher's directions …” – this is clearly not how you address God in a prayer. Exaudi nos, Domine &c., on the other hand, could be translated as "hear us, Lord" (in English, “hear our prayers” would be more idiomatic; exaudi preces nostras would certainly not sound wrong in Latin either).
