[wildleg]

put your tongue on tip, and connect your right hand to ring.

you will likely feel nothing.

have someone within sight ring the phone. you will taste the AC.

disclaimer: I will not be held responsible for anyone trying the above. Especially pansies.

 

[wildleg]

the phone has dc on it. an ac signal is sent to ring it. the ac and dc are on the same 2 wires. think of waves on the ocean. waves on top of the tide. some times it adds, sometimes it subtracts. in this case it is additive. put a voltmeter on your phone and watch when you ring it.