What are VBAC Women Seeking and Sharing? A Content Analysis of Online Discussion Boards.

Background: In the United States, one-third of pregnancies result in a cesarean delivery. In subsequent pregnancies, mothers must decide whether to pursue a vaginal birth after a cesarean (VBAC) or a repeat cesarean delivery. Pregnant women frequently turn to the Internet for support and information.

Discrimination of frequency variance for tonal sequences.

Real-world auditory stimuli are highly variable across occurrences and sources. The present study examined the sensitivity of human listeners to differences in global stimulus variability. In a two-interval, forced-choice task, variance discrimination was measured using sequences of five 100-ms tone pulses.

The salience of enhanced components within inharmonic complexes.

A subjective listening task was used to measure the salience of enhanced components using typical intensity-enhancement stimuli, time-reversed versions of those stimuli, and stimuli which contained a frequency shift of the target component. Twenty-five listeners judged whether or not a pitch "stood out" within an inharmonic complex. For comparison, judgments also were made for stimuli with a single segment that consisted of a simultaneously masked target.

Spectral and level effects in auditory signal enhancement.

Auditory enhancement refers generally to the increased perceptual salience of a spectral region when that region is preceded by its spectral complement, e.g., reinserting a missing component in a harmonic complex makes that component "pop out.

The effects of unmodulated carrier fringes on the detection of frequency modulation.

Detection thresholds for 100 ms of either 5- or 20-Hz frequency modulation (FM) were measured at various temporal positions within a 600-ms, 4-kHz pure-tone carrier. The results indicated that the temporal position of the signal relative to the fringe influences detection thresholds, including an effect that is reminiscent of auditory backward recognition masking. A task involving frequency increments, rather than sinusoidal FM, yielded similar results.