What is the tube between the air box and plenum called?

[Gary H]

I'm sorry, but can someone spell it out to me: I can find references to Helmholtz resonators relating to noise suppression...and that's it.
Having an expanded air reservoir POST MAF/Throttle body can make a huge difference to the available torque - I had this bulbous looking cross-over pipe on my old Miata and it made a huge difference...but this is um-metered air before it gets to the throttle body.

So the Helmholtz resonator on the snorkel is there for added torque?

And there was me thinking it was ll about noise reduction and passing certain EU noise levels...