As far as the films show us they can at least see in the visible light spectrum, and very likely can see outside of it since they dig the dark (and possibly know humans don't).
And based on Ripley8 they have heightened something. My guess is hearing from her being able to remotely sense if corridors are clear, the moving Auriga and Wren and co coming for Call.
The RPG had a great idea that they can communicate by changing colours on this heads outside the visible spectrum enabling them to communicate in a vaccuum.