Detecting single‐cycle frequency modulation imposed on sinusoidal, harmonic, and inharmonic carriers

TLDR: In this paper, the authors measured thresholds for detecting frequency modulation (FM) of various carriers in quiet and in noise using a single cycle of a 12.5 Hz sinusoid modulator.

Abstract: Thresholds for detecting frequency modulation (FM) of various carriers were measured in quiet and in noise. The carriers were either pure tones, harmonic complexes, or inharmonic complexes. The modulator was always a single cycle of a 12.5‐Hz sinusoid. When the carrier was a complex tone, each component of that carrier was modulated by the same percentage of its starting frequency. This is the form of FM that occurs when the fundamental frequency (F0) of a complex sound is modulated. Threshold was defined in terms of this percentage frequency change. Two phases of the modulator were used, producing percepts of either upward or downward frequency glides. Experiment 1 used sinusoidal carriers with frequencies between 200 and 2400 Hz. Thresholds were constant for carrier frequencies of 1200 Hz and above, increased below 800 Hz, and were higher for the ‘‘down’’ than for the ‘‘up’’ glides, especially with low carrier frequencies. Experiment 2 measured thresholds for carriers consisting of three adjacent harmon...