Why is my phone creating a high pitch ringing noise randomly and when playing audio and what can I do?

I’m not sure if your phone is an iPhone 7 but there used to be an issue on it where high pitch noises were being created, if that is the reason you should probably result in having a quick check in at Apple and speaking to the Genius Bar. If else it is probably either one of two things, a hardware issue or a software issue. The hardware could have something stuck in the actual audio so for this I would try putting headphones in to see if the sound goes away. If it does then you can confirm it is a hardware issue. Call up your phone manufacture or your provider for help and support.

If it’s a software issue report the problem to apples/samsungs/brands support centre and hopefully they will fix it in an update yet to come.

Hope this helps!