The present study examined how well individuals could differentiate between two different types of signals (early and late decels) in maternal-fetal heart rate tracings with and without the use of a visual aid. Twenty-one undergraduates twice viewed 80 simulated images under four different signal-to-noise (S/N) ratios. Further, the late decels were delayed in 4-sec increments. In one block of trials, the images were presented without a visual aid, and in the other block a visual aid consisting of a large turquoise crosshair was overlaid on the images. The results indicated that lower S/N ratios and shorter onset delays made signals more difficult to distinguish. However, overall levels of accuracy were significantly higher when the visual aid was present. These results provide initial evidence that utilizing visual aids can enhance the ability to detect critical signals in maternal-fetal heart rate patterns.