Wired Ring Door Bell - wired through current electric door bell UK

Hi everyone New to Ring, I have purchased a wired door bell, I already have a button door bell, chime located in the hallway with mains power to it. I purchased from Screwfix the 8 to 24v transformer, I connected everything and its working all good. The transformer is making a loud buzzing sound and as its located in the hallway you can hear it and the toilet the other side of that wall its loud too. I connected the wires up last night, I used 12v option for one and 24v for the other to the button outside, when I connected outside to the Ring, I just used either cable - my question is does it matter which goes to which and have a I used the correct 12v or does one need to go in the 8v. Maybe this would reduce the buzz sound? Also any suggestions for box/case that I could use around the transformer to reduce the sound. Any help is welcome Thanks Luke.