So I'm looking to make a mask for Halloween that acts a bit like the Arkham Knight from the Batman series in the sense that it scrambles your voice...does anyone have any advice on where to begin? Because all I can find from google is novelty ones (handheld etc) or voice recognition modules and I want this to be in real time...I was thinking of a microphone inside of a helmet and then two small speakers externally to a helmet...
You are off the a good start with the microphone and speakers. Then what? Why do you think an Arduino might be involved and how? How does voice scrambling actually work?
Adafruit has a voice changer tutorial.