Loud is relative, I suppose. Parakeets have nothing on cockatoos for being loud birds, plus they're much more suitable as pets.
I would also recommend someone considering adopting a parakeet (or any bird) to make sure there is a veterinarian in the area who does take care of birds. Many vets don't.
Birds are often placed in the "exotic" category, so a prospective owner needs to do some research as to whether his or her bird will have good care from someone accustomed to caring for the unique needs of birds. This is just a basic tenet for anyone who wants a bird.