I find the road noise coming from non-bitumen surface very loud and immersion breaking.
Can you please adjust the volume of the associated road noise (cobble/wooden bridge/grave) to match those of the bitumen
What I have done in the past to fix this, is unpack the soundmedia.bnk file - this contains the bulk of the offending sound files. Then convert the WEM files to OGG to listen to them. I have then been able to use the lower volume sounds within the pack to replace the loud one - repack the soundmedia.bnk and this has fixed it.
However with the new map Makuri Islands, this does not work any more for some reason, so now I am reverting to muting the sound system when I go over these sections of roads.
PLEASE do something about this as I love ZWIFT and really enjoy the total experience which includes all the sounds/environment has to offer as it is very motivational.
The other option is to include another slider that will allow the road noise to be separately reduced, but this would involve quite a bit more development, rather than just editing the sound files and reducing the volume.
https : // forums . zwift . com / t / cobble-and-waterfall-sounds-way-too-loud / 525944
I have found other people that have posted in various subforums/posts that have experienced the same issue, and one post pointed out a link to a @Shane_Miller_GPLama video stream on YouTube JEANr6XzkAs. If you start at 12:00 minutes into the stream you get an idea of the nice sound for the road, then at 12:35 - BAM incomes the cobbles and drowns out everything.
I hope you understand the issue.