On any installation a sounder should be located near the may entry point to the building. This should be on a separate circuit (conventional) or on a section of the loop that is protected by isolators (addressable).
The point of this sounder is to ensure that everyone who has left the building knows that there is still an active fire alarm.
If you connect it to the common sounder circuit of the rest of the building then a short circuit on the sounder line due to the fire could cause the sounder to stop, leading people to believe the emergency is over and they try and re-enter the burning building!
The sounder does not need to be located next to the panel but should be somewhere where it can be heard by the people who have evacuated and where the cable run is minimum to reduce the risk of not sounding due to cable fault. Placing the sounder too close to the panel can be problematic as people can’t talk to service technicians on the phone while the panel is in alarm and it results in people silencing the sounders prematurely in order to interrogate the panel.