18 month old not talking at all

My 18 month old nephew does not talk or even blabber at all. He will sometimes, and I mean once or twice a day, say “wowwww” or say like “ah ahhh” like small babies do. He does have a pacificerin his mouth a lot of the time. He goes to daycare and also doesn’t talk there. Should my brother take my nephew to a speech pathologist?