I hate to sound negative here, but the "DUH-DING" sound is still a FAR cry better than the windows error sound. That said, there's really not much stopping you from replacing ./.steam/resource/warning.wav with your own preference of non-irritating sound effect.
Hope this Helps!
Bug is that it's default, not that it can't be replaced.
@Gartral actually, you can't replace it because steam will just overwrite it. I could stop that by using
chattr +i resources/warning.wav but then the updates fail. Every time I start steam, wants to update and fails. Probably no new updates will be successful unless I change the file back.
Nothing extracted yet.
The main occurrence of DUH DING has been fixed with the update that allows the client to be interacted with when verifying cache, however DUH-DING still exists in Steam files and hasn't been replaced by an error sound that isn't horrible yet. Since the error sound still plays under certain situations, such as when Steam runs into some kind of error relating to interactions, the DUH-DING sound needs to be replaced as soon as possible so that Steam is no longer entirely unpleasant to use.