Test bursts stay within an eighth of the low-frequency masker’s period

Evidence

From the curves it becomes clear that a masking-period pattern can be measured only in that frequency range in which the masker produces a masking effect. The second boundary condition can be seen clearly in Fig. 4.32b where the time functions of the masker and of the test signal are indicated. The test signal has to be short in relation to the masker period, i.e. shorter than one eighth of the masker period. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 569