Different Ring or Message based on Extension call coming in on

Phone system information below.
Issue: I have a phone that is setup with 2 different extensions - each extension representing a different company. When a call comes in, the headset rings the same sound for either extension. The receptionist may not be at the desk to see which Extension/Line it is coming in on; she is able to pick up the line by pressing a button on here Headset. I need a way for the receptionist to differentiate which Extension/Line the call is coming in on.

I have looked for a way on FreePBX for some setting to play a recording prior to picking up.

I figure the solution can either be on the phone system side to play a sound byte prior to answering. Or, there may be a Headset that can be smart enough or programmed to ring different tones based on the extension.

Any ideas?

CentOS 5.2
Polycom Soundpoint 501
Plantronics C054 Headset