Many times in audio, we use digitally rendered room acoustics, or reverbs. Digital reverbs are great at cleanly creating large spaces such as concert halls and churches, but for the smaller spaces that we often need in commercials, it’s hard to beat Impulse Responses.
In a nutshell, an Impulse Response (IR) is an acoustic sample of a real space. You setup a speaker and a microphone and record a tone sweep of the room. By comparing the original tone with the recorded version, the program can derive the acoustics of the space. Another way to create an IR is by recording a loud impulse in the room. Often a starter pistol will be used, but a good kid-friendly substitution is a large balloon! You set up and record a stereo mic as you pop a balloon and voila, you have an Impulse Response!