Abstract: A measurement system is composed with a repeatable inspiriting sound source associated with a microphone fixed on the slowly rotating platform (RRS), which is equivalent to a round microphone array composed of many perfectly matched microphones. Based upon this system the theoretical analysis of sound intensity in the field consisted of direct impulse and reflection is presented. Therefore not only time characteristic but also spatial characteristic of room impulse response can be obtained. Then typical applications has been analyzed and discussed in this paper