I'm zooming in on the keyword "Pick".
In your pickup group you must have it set up to do notification (signalling type). I'm using V7 speak here, but V5 was the same way as far as I can remember - you have options of having it flash the LED, have it make a single beep, or a triple beep, place a message on the display if a display phone, etc. If you look at your Pick group in Assistant look at the Suppl Data tab. If signalling type is set to None then you will not be notified of a call coming into a Pick group.
If you are talking about members of a Communications group (Com group, Intercom group) the phone you are attempting to call should make an alert tone and then open up the microphone and speaker so you can reply. I think that tone is a system-wide parameter, but would depend on if the user's volume is up.
If your Pick or Com group is of analog phones I think the only notify type you can have is a single short or triple ring, considering there is no display.
Don Bruechert, Voice Comm Analyst II
CareTech Solutions @ Holy Family Memorial
Manitowoc, WI, USA