High-speed computers and digital signal processing have brought us to the point where it is possible to hear a convincing simulation of the acoustic environment of an auditorium. A number of researchers around the world have contributed for years to this field and they have now assembled the major pieces of the puzzle to make this powerful tool, called ``auralization,'' work well enough to judge acoustic quality. One needs a computer model of the acoustic space including placement of sources and receivers, an appropriate source signal, a binaural spatial transfer function from free-field pressure to eardrum pressure, and a headset which has a known equalization function from the electrical signal to the wearer's eardrum. A typical auralization session first runs the room computer model gathering sound ray arrival data at one receiver from a source. This receiver signal is then convolved with the binaural HRTF to produce a binaural electrical signal for the headset, which is equalized to achieve flat subjective response for a particular headset. The results are astonishing but positional accuracy in 3-D space is yet to be completely evaluated. Auralization provides an extra and independent layer of design security. Importantly, acoustic disasters can be avoided.