Why is it ringing

My granny has a VIVINT home security system and it’s worked fine with some minor issues but recently I woke up and heard this ringing. Originally I thought I was trippin but then I walk by it and it got louder so I look up and thought it was the smoke alarm or something, so I go wake my granny up and ask her if it rings like that regularly and she asks what am I talking about so I show her and we discover the security system ringing anybody have explanation?