Fruit and vegetables carving on topic power of speech

The first thing that comes to my mind is a base such as squash or melon carved into a face or at least a mouth, with a series of intricate, contrasting, and graduated (largest first, smallest last) flowers/botanicals carved from various fruits/vegs rising from the mouth. Based on my experience carving and making such showpieces, this is just my first practical idea that matches your theme as I understand it. I recommend brainstorming as many ideas as you can, then keep going as that is when your best ideas will appear. Think abstractly! Good luck!

It's a huge topic.
First thing I'd do is define it, then work out visuals.
E.g., free speech, persuasive oratory, commercial speech.
Or if you have a visual concept, work out its description before you start carving.

Unfortunately, I have no clue (papaya parrots?) but you do get my early nomination for question of the week.