A "beep tone" refers to a short sound or beep that is often used to indicate an alert or notification. It typically serves as a brief signal to grab your attention or convey a message. Full definition
When the system shuts off due to low battery charge, or due to three hours of operation since the ignition has been placed in the ACC position, the audio exciters emit an audible beep tone 30 seconds before the system shuts down. (hondanews.com)
If the feature is activated, the digital assistant will replace simple voice responses with a beep tone. (techtimes.com)
They emit a beeping tone to let you know when you're approaching an obstacle behind your vehicle and then turn into a solid tone to let you know you're a foot away. (cars.com)