Hardware question: external ringers

Hello all,

We have some phones (Polycom IP301 & 501) that are in loud environments. Some of my users are complaining about not being able to hear the phone when it rings, even with the volume turned up. I’ve bumped the gains up a little bit, but it’s still not loud enough.

Does anyone know of some kind of external speaker or ringer that will work with these phones? Maybe something that plugs into the headset jack and rings or flashes a light or something when the phone rings? I’ve googled to no avail.

Failing that, if anyone knows what the pinout of a standard headset jack is, I though maybe I could make my own ringer based on the signals from the headset jack. I’m assuming the phone sends the ring there as well, but I could be mistaken.

Our old phone system had an option like this, but they would just take the phone apart and solder wires onto the speaker in the phone and then run that through a small amp that was hooked up to a bullhorn-type speaker. Not the most elegant solution, but they said it worked well.