The Two-Microphone Method in the Impulse Response Domain

摘要

The two-microphone method is an ingenious technique for sound reflection coefficient measurement. By sound propagation theory and the measurement of the transfer-functions of sound pressure at two sound field positions, the reflection coefficient of a surface can be determined from measurements made either in free-field or tubes. Although the main calculations to obtain the reflection coefficient are based on the transfer-functions, a previous clean-up of their associated impulse responses is useful to isolate those reflection components which are crucial for the calculation and to suppress all other components. This minimizes notches and ripple stemming from interference with unwanted components. Some results are presented for plane waves in a tube for rigid and sound absorbing surfaces.