I have installed on my computer sonar 3 and Sonar Platinum . And both of them give me the same problem. Every time I want to play sound in audio browser it plays distorted sound majority of times. Some audio files sounds OK. It's been like that even before I installed sonar platinum. I don't remember having this problem with Cakewalk 8.5
Any ideas would be very apreciated

Check your "Preview" bus for clipping (on the distorted files) and report back.
 
Welcome to the forum.

That's exactly what it sounds like Beep.
 
Some of them have to be attenuated severely in order not to overload.
 
For this reason, I always stick a T-Racks Brickwall look ahead limiter on my preview buss which (can) clamp down quite heavily but also quite musically.
 

When previewing regular wav files make sure "Preview At Host Tempo" is disabled in the Media tab menu

Thanks everyone for responses. I tried everything suggested . It's better now, but still lots of audio files sounds really weird. But if I drag it to track it sound normal. Really strange