For the past 2 years, we’ve had 4 DSC PG9922 PowerG 915MHz Wireless Glass Break Detectors installed throughout the first floor of our house. Ever since, we’ve been hearing very subtle, quiet chirps coming from the area of the glass break detectors - just often enough to remind us that we can’t explain where the chirps are coming from, but not often enough or loud enough to actually be annoying or cause us to do anything about it. Is it possible the glass break detectors emit quiet chirps on some cadence?