DING <number-of-times>

DING rings the bell. This sophisticated technique is mainly used within CMD and DO files to get the operator’s attention, perhaps because input is required or an error has occurred.

Under Windows, and most terminal emulators (such as ZTERM), this will play the "System Default" sound. (You can change the WAV file associated with that sound from the Sound applet of your Control Panel, no doubt amazing and delighting your colleagues by setting it to a shrieking woman, theme from Thus Spake Zarathustra, or a gastronomic by-function.)

If you do not have a sound card, or are using a dumb terminal, you will be at the mercy of the default hardware bell sound (and loudness, or lack thereof).