Question About Sirens in Devices

Newbie here. First post (and, yes, I searched for an answer before posting). Am I correct that there are sirens in the keypad and in the base station? I had originally bought a Dome siren to add to my great room area, but that's where the base and a keypad are, so I'm thinking that if those devices have sirens, I don't need the Dome siren. I'd appreciate help and advice. Thanks!