The study described in the release concerns the effect of nicotine on mice. Pregnant mice were given nicotine late in pregnancy. The offspring had reductions in hearing ability. The study went further, though, to implicate this as a specific developmental problem. The timing of exposure makes a difference. Nicotine apparently damages the acetylcholine receptors in the developing brain in utero, preventing normal hearing response in the adult.
The implication for human medicine is that pregnant smokers who are given a nicotine patch to prevent other harmful effects from cigarette smoke may still be at risk for infants whose hearing may be impaired by third-trimester exposure to the nicotine from the patch.