If this is an NEC IVS2/IPS with a call centerworx, then in the ACD Split data you will find a setting for Auto Answer. Check it then update the split. This will automatically send a call to an available agent and it will be automatically answered. They should be using headsets for this feature to be fully effective. It will also provide a "zip" tone just before a call is presented to the agent. With the split set to auto answer, you will want to remove the line key set for auto/manual. You do not want the agent turning it off or on at will.