Learning in discrimination of frequency or modulation rate: generalization to fundamental frequency discrimination

Fifteen initially inexperienced subjects were trained for 4 weeks (12 2-h sessions) in frequency discrimination with pure tones around 88, 250, or 1605 Hz, or amplitude modulation rate discrimination of noise bands, using modulation rates around 88 or 250 Hz. Before, in the middle of, and after this training period, pure-tone frequency discrimination thresholds (DLFs), harmonic complex tone fundamental frequency discrimination thresholds (DLF0s), and amplitude modulation rate discrimination thresholds (DLFMs) were measured in several conditions including the trained one. Training in pure-tone frequency discrimination resulted in significantly larger improvements in DLF0s when the test complexes contained resolved harmonics than when they were composed of unresolved harmonics. This result supports the hypothesis that the discrimination of the F0 of resolved harmonics shares common underlying mechanisms with the frequency discrimination of pure tones. Training in rate discrimination did not result in larger DLF0 improvements for unresolved than for resolved harmonics.