Impulse Response (IR)
Definition
A recording that captures the acoustic signature of a physical space or hardware device by measuring its response to a brief, full-spectrum test signal. Impulse responses are used in convolution reverb processors to recreate real acoustic environments digitally.
In Simple Terms
A recording that captures the acoustic fingerprint of a real space or piece of equipment. Load it into a convolution reverb and your audio sounds like it was recorded in that specific room, hall, or studio.
In Practice
An impulse response of a vintage EMT 140 plate reverb unit is loaded into a convolution reverb plugin, allowing the engineer to apply the exact tonal and spatial character of that hardware to any signal without owning the original unit.