Only tones exceeding a level-dependent masked threshold are audible in noise

Evidence

In this demonstration a pure tone is masked by white noise. The tone has a frequency of 500 Hz, the white noise has an overall level of 63 dB which corresponds to a density level of about 20 dB. You will hear six presentations, each with triplets of pure tones, masked by white noise. The level of the tone triplets is (in this order) 51 dB, 37 dB, 46 dB, 34 dB, 43 dB, 40 dB. Except for the second (37 dB) and fourth triplet (34 dB), the tones are above masked threshold and should be audible. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 3253

Categorization

• XREF: Illustrates the masking threshold concept formalized as the fundamental psychoacoustic relation between signal level and noise-induced audibility limits. — connects to: Pleasant sounds can mask traffic noise only at low amplitudes — Almo Farina, Soundscape Ecology: Principles,…, 2470