A CRT TV will generally make a 15.7kHz squeal because of the flyback transformer. Not everyone can hear this high: between ages 20 and 40 most people lose hear

A CRT TV will generally make a 15.7kHz squeal because of the flyback transformer. Not everyone can hear this high: between ages 20 and 40 most people lose hearing down from 20kHz to 10kHz.