The test consists in the measurement of the noise intensity at the output of a bandpass filter, and the estimation of the accuracy of the measurement. The confidence interval for the estimate is calculated under the assumption that the noise is stationary and Gaussian. This assumption is called "zero-hypothesis". If a considerable part of the experimental data is outside the confidence interval, then the zero-hypothesis does not hold. The effect of noise being non-Gaussian is investigated analytically. Experimental data of 1/f noise in GaAs epitaxial films are presented and discussed.