There is a certain vibrational pitch that makes people feel it in their back teeth, if on long enough it gives you a headache. That's where this voice comes in.
The Screecher is a voice that aims to be nasally in tone and often coinciding with being high-pitched, generally meant to sound unnatural and be obnoxious. If not obnoxious, it still makes them vocally in a very different register than most people.
It is typically used for The Ditz
or a very sweet and bubbly
girl. Some characters may not always have the voice naturally but slip into it when excited, angry or scared (like when they are screaming). Male characters rarely have this voice, but if they do it usually is done to convey an animalistic nature. If a man is going to have the Vocal Dissonance
of a woman, this kind of voice is often
Contrast the Guttural Growler
, whose voice instead feels like a subwoofer.