Preposition for “Lauschen”?

Answer 1

There is no preposition for the verb "lauschen". "Lauschen" is a dativ verb, i.e. the preposition often found in the English translation is expressed through a dative article, e.g.:

I am listening to the waterfall (with pleasure). = Ich lausche dem Wasserfall.

I am listening to the music (with pleasure). = Ich lausche der Musik.

I'm (secretly) listening to the conversation. = Ich lausche dem Gespräch.