Masked threshold always exceeds quiet threshold except when masker and test frequencies differ greatly

Evidence

The masked threshold is the sound pressure level of a test sound (usually a sinusoidal test tone), necessary to be just audible in the presence of a masker. Masked threshold, in all but a very few special cases, always lies above threshold in quiet; it is identical with threshold in quiet when the frequencies of the masker and the test sound are very different. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 397

Categorization

• DEFINE: Defines the masked threshold, the central operational measure of masking.