An IR (Impulse Response) pedal is used to simulate the sound of different speaker cabinets, microphones, and room acoustics, providing guitarists and other musicians with a range of tonal possibilities without the need for physical amps or speakers. By loading a digital model of a specific speaker or mic setup, IR pedals allow musicians to replicate the sound of classic amplifiers and cabinets, or experiment with a variety of virtual setups to create their ideal tone.

IR pedals are particularly useful in live and studio environments, where space and volume restrictions may prevent the use of traditional speaker cabinets. Many modern pedals and modelers, such as those from Two Notes, Headrush, and Boss, feature built-in IR functionality, offering musicians the ability to tailor their sound with great flexibility. With the ability to load custom IRs or choose from pre-loaded options, IR pedals can provide incredibly realistic tones, making them an essential tool for musicians seeking versatility and convenience in their setups.