If you live in Preston Hollow, then you may be aware that the city's Outdoor Warning System (a.k.a. the 'tornado siren') is regularly tested on the first Wednesday of every month at 12:00 Noon, weather permitting.
But for the next few months, the city sirens will sound off and on as maintenance work is performed. Residents may occasionally hear brief and intermittent siren noises, called siren "burps". So if you hear it, you're not imagining things. [where: 75230]