On a typical Western Electric 500 rotary dialler assembly, there are two sets of contacts--one to generate the pulse train and the other to short the speaker terminals in the handset (so one doesn't get blasted in the ear with loud dial pulsing noise.) When both sets of contacts (particularly the pulse contacts) are held open, one can monitor the audio path of their telephone line, including the idle-line noise and the ringing voltage.
I think there was a "box" term phreaks assigned to such a modiphied telefone set, but I can't remember what it's called. It's not a beige box (that's simply a phone cord with alligator clips at one end, to turn a regular fone into a buttset) or a "meeko" box (which is an interface device that sits between the fone and the line, to record the audio or put music onto the line.) Anybody have any clue?
(No name calling.)