Altiverb 7 is the highest quality convolution reverb made by the Dutch company Audio Ease. A convolutional reverb is a purely digital type of reverb that works by superimposing pre-recorded impulse responses (IR) on the received audio signal. In other words, the impulse responses of a specific room are recorded and then superimposed on a digital audio signal, resulting in the illusion of being in the space where the impulse response data was recorded.