Pure-tone intensity discrimination: some experiments relating to the "near-miss" to Weber's law.

Intensity DLs for pulsed tones (f = 1000 Hz) were determined at two sensation levels. As has previously been noted, discrimination was better at the higher level. The possibility that this effect reflects the subject's use of information from aural harmonics was tested using stimuli specifically designed to disrupt such information. These stimuli did affect discrimination, but only when they were at levels in excess of those which would be required by the usual estimates of aural harmonic magnitudes. Further experiments with interfering stimuli used three types of noise: wide‐band, high‐pass, and band‐stop. The noises had equal energies in the critical band around 1000 Hz and had spectrum levels in their respective pass‐bands of −60, −30, and −35 dB relative to the 1000‐Hz test tone. The noises had no effect on performance at the lower sensation level. At the higher level, performance was impaired, the greatest impairment being produced by the band‐stop noise, the least by the wide‐band noise. This was in...