It goes under the rule, clear microphone. I believe the rule about microphone should be updated. Clear, people can understand and good voice. Annoying ones cannot be CT. This is how you can have 2 bunnies with 1 shot. I said it before, rather they use the voice changer than we have to hear annoying small voice. Some voices are better than others, gotta admit that.
Also how will you know for sure that they are using voice changer? Me for example had a microphone and most people said it sounded like radio, again I am sure some thought im using voice changer.