Hard surfaces everywhere. The acoustical consultant in me takes one look at those pictures and wants to start crying.
Or, in an extreme example, the ones you see in anechoic chambers: https://www.google.com/search?q=anechoic+chamber&source=lnms...
The foam devices serve to both absorb sound energy, and to scatter the remaining sound energy at a variety of angles, where much of it will collide with other reflected sound waves and cancel out.
I needed some acoustic foam for a small project at home and found this place. They seemed pretty affordable (and had lots of colors) compared to other places, though I'm far from an expert and I was only buying ~$40 of foam so I didn't exactly spent too much time comparison shopping: http://www.foambymail.com/acoustical-foam-products.html