Could this sentence be used for the phrase, "the lawyer is calling again?" Thanks.
Yes. There is no difference between the present simple and present continuous in Swedish.
I heard advokaten ringer ren .... I should lay off max volume headphones
you're not too far off... the last R in ringer is really close to the beginning of igen, which sounds like the "-en" in "ren" ... (:
Does this specifically mean a phone call, or can it be used to call out to someone?
It can not be ~shouts. Either he is on the phone, or (less likely) he is pounding a church bell (or similar).