Hi piotrek1130sw,
From what you have described, I think the best approach would be to restore the original IDT driver, restart the computer, test that driver, then install the driver update, and test the outcome of installing the newest driver.
Use the following link for instructions to recovery the ITD driver using Recovery Manager. Restoring applications and drivers.
Once the driver is restored, restart the computer and test the audio. If the audio is good you can continue to use this driver, or you can reinstall the update and see what happens. IDT High-Definition (HD) Audio Driver.
If installing the newest driver causes the issue to occur but the recovered driver worked, I suggest recovering again.
If neither driver works I will gladly follow up and provide any assistance I can.
Please let me know the outcome.