I run Kali from a live boot USB. When I boot up a blue option screen appears along with a “ bleep” How do I stop the “ bleep” - it’s driving my wife mad. Turning the volume down on the LT has no effect. I guess it’s in grub, but I can’t find it. Any advice?
Disconnect the internal speaker on your computer. You might be able to turn off the internal speaker in BIOS, but not necessarily.
Also, this isn't really a Kali-Linux issue; any bootloader or OS that uses the system-bell (may not be the right term, but its a command/control in the firmware) will make sounds through this speaker.