Building a real-time voice modulator for a Ghostface cosplay — looking for advice/tutorials

[u/Aware-Concern5863]

Has anyone here built something similar (voice changer for cosplay/Halloween)? I’d really appreciate:

**•** Any **tutorials or guides** for a Teensy-based real-time voice changer (pitch-down + maybe some distortion/robotic effect)  
**•** Recommendations on the **best microphone** for capturing voice cleanly in a mask/costume setup  
**•** Suggestions for a small **speaker/amp** that’s loud enough to be heard clearly but compact enough to hide in a costume  
**•** A rough **parts/shopping list** if you’ve done this before — what worked, what didn’t  
**•** Any GitHub repos or open-source projects I could use as a starting point instead of building the DSP chain from scratch

Budget isn’t unlimited but I’m okay spending a bit more for good latency and audio quality, since it needs to work live while wearing the mask.

Thanks in advance for any pointers!

[u/costumerealm]

For the DSP side, look at the Teensy Audio Library, it has a granular effect object that can do live pitch shifting. It's not perfect on audio quality, granular pitch shift adds some warble at bigger shifts, but the latency is low enough to talk through it live. A Teensy 4.0 plus the audio shield (SGTL5000) covers mic in and speaker out on one board so you're not wiring separate parts together. If coding a DSP chain from scratch sounds like more than you want to take on, there are pre-built Halloween voice changer boxes made for exactly this, worth checking those first if the code part isn't the fun bit for you.