A couple of weeks ago we had an excursion to an anechoic chamber in the basement of the physics department at the University of Oslo. This room is a remainder from back when there was an acoustics group in Oslo (which later moved to Trondheim), and it was a pure coincidence that we discovered that the old room is still intact, largely thanks to Arnt Inge Vistnes. He also happens to be the person that first introduced me to the Fourier transform back in the days when I studied physics, so he got the challenge of holding a guest lecture for our students in sound theory on the topic of (…) the Fourier transform.