Sound/Audio Distortion on XPS 13

I cam across your profile hoping you can help me.

I own an XPS 13 - 9350 which I purchased last year.

The sound worked fine but then because distorted. So then I downloaded and installed a previous version of a driver.

Now on the 13th Aug I was asked to update my drivers by Dell. I did. and then the sound became distorted.

I called the support team who determined that its a software issue not hardware that's distorting the sound - quite possibly due to Realtek driver.

However Ive tried to uninstall this and reinstall and to install an older version but nothing.

Any help is appreciated.

Thanks