background noise vs ground noise

background noise and ground noise both are nouns.

Word	Noun	Adjective	Verb	Adverb
background noise	Yes	No	No	No
ground noise	Yes	No	No	No

As nouns, background noise and ground noise are synonyms defined as:

background noise and ground noise: extraneous noise contaminating sound measurements that cannot be separated from the desired signal

background noise (noun)	ground noise (noun)
extraneous noise contaminating sound measurements that cannot be separated from the desired signal	extraneous noise contaminating sound measurements that cannot be separated from the desired signal