The higher audiometric frequencies arguably are the most important for some tasks requiring fine temporal discriminations. Both modulation and gap detection thresholds improve with increasing center frequency of noise bands. For modulation detection, however, not all investigators are convinced that improved performance is necessarily dependent on sensitivity at the higher center frequencies. They point out that the high-frequency advantage for modulation detection may be a consequence of concomitant increases in stimulus bandwidth as a function of increasing center frequency of the noise band. To determine whether signal frequency or signal bandwidth is more important for modulation and gap detection, modulation and gap detection thresholds were measured for low-pass (LP) filtered noise (fc = 4000 Hz, bandwidth = 4000 Hz), high-pass (HP) filtered noise (fc = 4000 Hz, bandwidth = 2500 Hz), and broadband (BB) noise (bandwidth = 6500 Hz). Modulation and gap detection thresholds for the BB and HP signals were similar, and were better than thresholds for the LP signal. The ability to hear the higher frequencies of the noise signal apparently is more important for these tasks than is perception of signal bandwidth. [Research supported by Division of Sponsored Research, University of Florida, and American Cancer Society.]

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Modulation detection thresholds (as a function of sinusoidal amplitude modulation frequency) and temporal gap detection thresholds were measured for three low-pass-filtered noise signals (fc = 1000, 2000, and 4000 Hz), a high-pass-filtered noise signal (fc = 4000 Hz), and a broadband signal. The two latter noise signals were effectively low-pass filtered (fc = 6500 Hz) by the earphone. Each of the filtered signals was presented with a complementary filtered noise masker. Modulation and gap detection thresholds were lowest for the broadband and high-pass signals. Thresholds were significantly higher for the low-pass signals than for the broadband and high-pass signals. For these tasks and conditions, the high-frequency content of the noise signal was more important than was the signal bandwidth. Sensitivity (s) and time constant (tau) indices were derived from functions fitted to the modulation detection data. These indices were compared with gap detection thresholds for corresponding signals. The gap detection thresholds were correlated inversely (rho = -1.0, p less than 0.05) with s (i.e., smaller gap detection thresholds were correlated with greater sensitivity to modulation), but were not correlated significantly with tau, which was relatively invariant across signal conditions.

Higher education institutions in the United States have historically been tasked with the responsibility of scaffolding the moral development of students. Although empirical evidence suggests that attending colleges and universities can foster students’ moral development and reasoning, the effect of online higher education remains mainly unknown. The current study has examined the effect of two online psychology courses, Developmental Psychology and Research Methods Lab, and their respective assignments on students’ moral competence. The findings revealed that students’ moral competence in both courses was improved; this improvement was partly attributed to online group discussions in the Developmental psychology course. No other assignments were found to be significant contributors of students’ moral competence. Limitations and implications of the findings were discussed.