My Canon EF 85mm f/1.4L IS USM lens is making a noise I never heard before. It takes pictures and focus as usual but produces a constant ticking noise when the image stabiliser is turned on.
Many reviews I've seen and a lot of comments in various forums have commented on the sound that the EF 85mm f/1.4 L IS makes when IS is first activated, while it is active, and when it is deactivated.¹
The EF85mm f/1.4 L IS has some relatively large optical elements for the overall size of the lens. Larger and heavier IS elements mean more powerful motors are needed to move the IS elements. This is most likely the basis for the noticeable noises. Because the overall lens is smaller and has less mass and fewer other materials absorbing and insulating the sounds made by the IS unit it is more noticeable to users. The large IS units on those massive Big White Super Telephotos lenses also tend to be further from the camera and the ears of the photographer than the IS unit on the EF 85mm f/1.4 L IS.
Then there's also the "rattling" noise that any Canon IS lens can make if detached from the camera while IS is active, rather than 'parked' first. It's probably more noticeable with a relatively small lens with relatively large IS elements for the same reasons discussed above. For more about this, please see this Canon Digital Learning Center article.
¹ Here are a few of them: