The detection of differences in the depth of frequency modulation

摘要: Thresholds were measured for the detection of differences in depth 5-Hz frequency modulation (FM). In first experiment, listeners detected between sequentially presented sinusoidal carriers. The Weber fractions FM decreased from about 0.5 to 0.3 as baseline was increased 2.5% 20%, and slightly higher a carrier kHz compared frequencies 1, 2, 4 kHz. second complex carriers used consisting consecutive harmonics 125- 250-Hz fundamentals (f0's), bandpass filtered 1375 1875 Hz. Performance worse with these stimuli than carriers: f0 ranged 0.4 2.0 across listeners, roughly invariant depth. 125-Hz showed steady decrease 3.2 0.6 so that threshold corresponded, approximately, constant increase depth, independent absolute detectability may have been limiting factor lower two depths at this f0. final psychometric functions simultaneous across-frequency Three conditions tested; be 666- 1500-Hz pure tones. condition tones, both f0's 250 Hz, 125 625 Hz respectively. third similar, except (complex) had different 111 performance extremely poor, even when discriminated 10% 50%. Listeners did perform substantially better, however, on condition. implications results idea use perceptually segregate concurrent sounds are discussed.