bonk
n.β Β«A simple anecdote was told about how one of the cityβs firefighters was concerned that the “NC bonk”βa feature designed to alert him when the radio was out of signal rangeβhad not activated recently and thus was broken.Β» ββKansas City upgrades and training win praises” Channels Close Up Oct. 1, 2004. (source: Double-Tongued Dictionary)