I was getting random Device Connect and Device Disconnect sounds and no notifications or messages as to why. My USB printer was connected but turned off so the only other connected devices were my monitor, speakers, keyboard (PS/2) and USB mouse.

Disabling/enabling options did nothing to stop the sounds. I turned off all Notifications & actions, AutoPlay and the USB "Notify me if there are issues connecting to USB devices" option and my computer still made the Device Connect and Device Disconnect sounds.

After playing with it for a while I noticed that the random sound occurred when moving my USB mouse but the sound did not happen every time I moved the mouse. I found that by just moving the mouse around I could make the Windows Device Connect and Disconnect sounds play and even several times in a row by moving the mouse around quickly or erratically.

The USB mouse was working correctly other than not being able to wake the computer from sleep even though it was set to do so in Device Manager. I switched it out for another Dell 5 button mouse and have not heard the random sounds since then (other than when I actually connect or disconnect a device). The replacement mouse also wakes the computer from sleep mode.

I found several posts where the random sounds were caused by a USB device. Either a USB cable, a USB mouse or a USB3 hub. I suspect for most people who are getting these random connect and disconnect sounds it is because of a USB device but not always, see this device connect/disconnect thread. I would start with disconnecting or replacing your USB devices, including built-in memory card readers, one at a time until the random sound stops, that device should be the culprit.