The OnePlus 7 Pro has been received with an overwhelming amount of praise, but of course, no product is perfect. We've heard that some people (including our own Artem) have issues with phantom touch inputs on the screen, and now, another less severe problem is making the rounds. A few users report that they're hearing high-pitched interference noise on the earpiece while on phone calls.
On OnePlus's forums, opinions are divided. Some people report that their phones always have this high-pitched noise while others don't experience it at all or only sometimes. There is speculation that the issue might be related to carriers, as one owner reports the noise appears to be more prominent on AT&T HD calls, but the same person never had any problems with other devices on that carrier. Plus, another forum member remembers that his OnePlus 3T had similar difficulties that were fixed with a software update.
Thus, let's hope that OnePlus quickly identifies where the problem originates from and pushes an update to affected users. Again, this doesn't seem to be a widespread issue, but it hampers one of the fundamental features of a phone, so it's in no way irrelevant.