One of the new features of the EOS R is the control ring. Similarly found on the Canon PowerShot G7X, a ring that you can use to control things, at the tip of the lens. Like the G7X, the ring does click when rotated and can be heard. According to Canon you can get it disabled (YouTube):
“This clicks will make a slight audible sound as you rotate the ring. For critical video shooters concerned about the possibility of recording this sound, Canon service technicians can modify your RF lens and remove the click stops for a fee.”
That’s right. Not with a button like on the G7X MarkII but sent back to the service center.