L4-1.8L,Clicking noise in idle (link of Video of noise included)

My car has been making a lot of noise when it’s in idle. As soon as I hit the gas the noise completely disappears and otherwise the car runs perfectly. My car is a 2003 corolla with about 155000 miles on it. The noise is a clicking sound and has gotten slightly louder from when I first noticed the noise about 3 years ago. I have a little bit of video footage on this link of the noise that I notice. HERE'S THE LINK, you can copy/paste it onto your browser (https://youtu.be/ifVOQzMCs1M) The video footage is taken at a weird angle but you can hear the clicking noise in the background. As so