Effect of masker level on detection of a tone in pseudorandom noise

Masking of a tone by a sample of pseudorandom noise was studied as a test of Poisson-counting models of auditory detection. The noise waveform did not change throughout the experiment and the 1000-Hz signal was added to the masker in fixed ’’phase.’’ Three different samples of noise were utilized. Masking functions for three listeners showed that the signal-to-noise ratio at masked threshold did not change as the level of masker was increased from 30 to 80 dB SPL. The finding of Weber’s Law for these stimuli is not predicted by Poisson transduction models of detection.