Disable audio feedback when scanning a barcode (MC18)

I'm trying to find information about how to completely disable the audio feedback when scanning a barcode. I made changes in the profile Manager for Data Capture -> Data Input -> Barcode -> Scan Parameters -> Audio FeedBack Mode and set it to "Disable", but it doesn't make any difference.

 

The audio is _very_ loud and we _really_ want to completely disable it. I've looked through the API documentation without finding anything.