Three-point method for measurement in a impedance tube using pseudorandom signal excitation

A new method measuring acoustical propertiest-Threde-Point method using pseudorandom excitation is discussed in this paper and its error is analysed in detail.Experiments have been done to compare the Three-Point method with SWR method and TTF method.It is shown that the results of the new method are in good agreement with SWR,and the shortcomings of TTF are overcome.