Simple Explanation

How a system reacts when you hit it with a super quick, sharp sound like a "click."

Concise Technical Definition

A system’s output in response to a brief input signal (impulse), representing the time-domain characterization of its behavior.

Layman-Friendly Analogy

Like clapping in a room and listening to how the sound bounces and fades—this reveals what the room "does" to sound.

Industry Usage Summary

Used in acoustics and digital signal processing to analyze how systems (speakers, rooms, or software) affect sound over time and frequency. Often measured to derive EQ, reverb, or speaker correction filters.

Engineering Shortcut

IR = time-domain response to impulse; contains full system behavior info.

Full Technical Explanation

The impulse response of a system is its output when presented with a theoretical impulse—a signal of infinitely short duration and infinitely high amplitude with finite energy. While such an ideal impulse can't be physically generated, in practice, very short-duration pulses serve as approximations. Because the impulse contains all frequencies at equal amplitude, it is ideal for revealing how a system behaves across the full frequency range. The resulting time-domain output—the impulse response—uniquely characterizes the system. Using a Fast Fourier Transform (FFT) on this response yields the system's frequency response (amplitude and phase). In digital signal processing (DSP), impulse responses are used in convolution reverb, speaker correction, and system identification.