Text to Speech Bullhorn

Step 4 Next steps

I have not done these things yet, but some ideas:

Disable the siren button. It's dangerous.
Add a sound activated LED for visual feedback when it's working.
Use the same principal to connect to a walkie talkie or cell phone.
Get a bigger bullhorn, much bigger.
Use a speech to text software to translate in the other direction.
Learn ASL.

Let me know in comments if you have more ideas!