Alarm Sound In Large House

I live in a fairly decent sized house and have the home base on my main level. The doorbell and alarm siren essentially can’t be heard on the upper and lower floors. It would be nice to have the alarm go louder and/or some alarm extenders that could be placed in other parts of the house to travel or extend the doorbell and alarm sounds. Note:I have my alarm setting at max. Note:I’m aware I can hook my doorbell into my existing doorbell system and it would be louder.