I have a quote for a brand new IPO Basic Edition to replace the customers existing 30 year old key system. On one of the extensions in the shop, there is an external loudspeaker that has been hardwired (presumably in series) with the loudspeaker on the extension. That way when someone calls or pages that extension, the it is also heard on the overhead speaker as well.

How can something similar be accomplished using the IPO and 1416 phones?