When i use new minecraft launcher for the first time - i try to play 1.6.4. It downloads files (like 1.6.4.jar) and then the game starts. When i try to play - there are no sounds, but in mc options and windows it is set up to 100%.

Then, i downloaded an old launcher from https://minecraft.net/en-us/download/alternative .
And pressed "play" there. MC game starts with no problems and all the sounds.

So, i think, that there is a prolem with new mc launcher.