The sound source identification is used to find where the noise is radiated from. To reduce noise, it's more effective to add a soundproofing treatment to the noise source directly than the countermeasures on the sound propagation path, like noise barrier. To achieve this purpose, noise source identification technology is come up. Before inventing the sound source identification technology, for example, each noise source contribution cannot be found if all production lines are stopped before measuring the sound pressure level. Or, for developing a quiet cabin of the vehicle, if the noise source ranking and contribution cannot be found before countermeasure, the improved plan tends to be "too much"; it seems difficult to achieve both lightweight design and its sound proofing capability. Taking advantage of the sound source identification technology, time for the testing can be reduced, number of the prototyping can be reduced, so, the quiet condition can be achieved with saving money and time. Nittobo Acoustic Engineering, the pioneer of the noise source identification and visualization, released the omni-directional sound source identification and visualization system Noise Vision in 2002. It is the first system in the market, and truly user-friendly system for the engineers. Since then, various customers has been used Noise Vision. Generally, the system using microphone array is very complicated to use. However, Noise Vision is completely different from them. Noise Vision is very easy system to use with simple operation, and provides the noise source visualization on the pictures quickly.