noun

A short, high-pitched sound emitted by electronic equipment or a vehicle horn.

leave a message after the beep

audible warning,purr,purring,ring,ringing,note,tone,beep,bleep,meep,warble,signal,alarm,alert

intransitive verb

(of a horn or electronic device) produce a short, high-pitched sound.

radio receivers squawked and beeped

purr,sound,reverberate,ring,beep,bleep,warble