Uniden LRD 766 - Manual (Page 17)

CITY OPERATION
In highly populated areas, you may encounter many devices that
use the same frequencies as radar signals, such as motion
detectors, automatic doors, and intrusion alarms. These devices
may trigger an alert called “falsing.”
To filter most of the weaker signals and get the most accurate
radar signal recognition, press
city to turn on the City Mode.
In City Mode, the combination of visual and audio alert tones
varies based on the strength of the received signal.
16
If you use both the
Audio Only Alert and
City modes, you won’t
receive an audio alert
until you are very
close to the radar
source.