"I hear a weird voice at midnight."
Translation:Aku mendengar suara aneh di tengah malam.
Still trying to wrap my head around the usage of "yang". Can I use it in this sentence
Aku mendengar suara yang aneh di tengah malam?
Why or why not?
Yes I think you can use it like that. It has a few different uses and meanings, it is quite a used word. How you use it there I think translates as that is or which is. So the sentence becomes " I hear a voice that is weird".
For a little reason it could translate into something weird like " I hear a voice that is weird for the middle of the night" but I doubt it, an Indo would need to clarify that though.