GXP1630 Busy sound


Hello Everyone

We have five GXP1630 configured at a clients site with three accounts on them connected to the PBX. I would like to ask that, because the users usually are busy talking on the phone in the one account(line) of the GXP if someone calls them in the other account(line) is there a sound that we can configure on the phone to inform the user that the second line(account) is ringing if for some reason the user is not looking at the display of the GXP.
OR an option(sound) at the GXP to inform the internal caller that the user he is calling is busy on another line(account)?

Thank you