not belonging or appropriate to something
extraneous - irrelevant
Something ‘extraneous’ by its nature comes from the outside. In a literal sense, that can refer to things like light or noise, for example. However, this formal word is most commonly used figuratively to express something that it is not suitable, necessary, or directly related to a particular situation or a subject being discussed.
I’m not going to answer your questions because they are extraneous to the matter that I am currently discussing.
My extraneousness to the facts means that I am not best placed to judge the situation. You would be better off asking somebody more intimately involved.
The noise wasn’t coming from the room. It was being generated extraneously from the street outside.