Does anyone know how to add the demon voice effect?

[Blu]

Like on Eminem's songs. He has that demon voice (3rd hook of 3AM).
I tried changing the pitch, but it just doesn't sound as good.

Tips?

Btw, I'm using Audacity

[Atone]

there's 2 ways i do this

1. layer it twice, on 2nd layer Slow down the speed some, move it a tiny bit to the left

2. Slow down the speed, and change the pitch

[Blu]

there's 2 ways i do this

1. layer it twice, on 2nd layer Slow down the speed some, move it a tiny bit to the left

2. Slow down the speed, and change the pitch

OMG. THANK YOU. SHIT SOUNDS AWESOME!!1

[BigBoss]

No.