ring_bell = False refers to whether the bell will ring when user input is required. The issue noted by Jarek is a problem where printing non-western characters on a windows cmd.exe will result in beeps.

Redirecting stdout to a file will turn off transliteration, which solves this problem, even though it shouldn't change anything when the output is to stderr..

Ah well, it's good to know there is a workaround.

Merlijn