What is the difference between the two?

Cocobolo is an exotic hardwood. Acrylic is a plastic.

I know that...lol
What about sound? Any different?

Cocobolo is going to be richer but softer and tends to change sounds with weather - the acrylic is going to be a harsher sound but I can get more range out of it and it is unaffected by weather - I have a wooden call for closer work and an acrylic call for open water.

LMAO

I think Cocobolo tends to be less likely to sieze up when it gets wet because less condensation collects on wood than plastic. Very handy when it is very cold outside especially if you blow your call a bunch.

get both...each has its better points in different situations

Wood calls are finicky. They sound and act different in different conditions. I have several wood calls and they stay at the house in a display. Acrylic calls are the same no matter the conditions. Every time you pick it up you will get the same sound and tone. They also don't swell and crack like wood sometimes does.

Get acrylic.

Couldn't agree more