Frequency discrimination at the threshold

Abstract

A 4-AFC task was used to determine absolute thresholds in noise and frequency DLs. Frequency DLs were determined by keeping the frequency increment constant and varying level. Observation intervals were marked by precursor tones which set up a rhythm for the subjects, and helped him to remember what to listen for. Tones pulses were asymmetrical triangles with a 2 ms rise time and a decay of 14, 62 or 254 ms. For the longer durations the frequency DL at the masked threshold (Pc = 0.625) was about 16 Hz (standard= 1000 Hz). For the 16 ms tone pulses the DL was about 64 Hz. See also: Some notes on frequency discrimination and masking, B.L. Cardozo (1974) Acustica,31,330-336.