How many times have you had to yell for the kids or your spouse through the house, just to get a quick answer? Cut the shouting, and look at phone systems and intercoms instead!
Telephone systems allow you to direct incoming phone calls to the approrpiate extension, so your kids calls only go to their phone. Intercom systems let you answer the door by just picking up the phone. And the yelling? How about using paging features to get their attention instead?