Impulse Response

An impulse response is the complete time-domain record of how a room responds to an ideal impulsive excitation (a Dirac delta function). It captures all acoustic information about the room—direct sound, early reflections, reverberation, and room modes—at a specific source-receiver combination. ISO 3382-1:2009 §5 specifies measurement methods using interrupted noise, MLS, or exponential swept sine signals. From a measured impulse response, virtually all room acoustic parameters (RT60, EDT, C80, D50, STI, IACC) can be extracted through mathematical processing. Impulse responses are also used for auralization by convolving them with anechoic audio recordings to simulate how music or speech would sound in the measured room. The quality of the impulse response depends on the signal-to-noise ratio, with modern swept sine measurements achieving 60+ dB dynamic range.