The discovery that adolescents whose mothers had smoked during pregnancy had defects in both high-frequency and low-frequency hearing suggest that the developing auditory system is damaged by in utero exposure to tobacco smoke, according to Dr Michael Weitzman, a child health researcher from the New York University School of Medicine, who led the study.
In another study, Weitzman and his colleagues found exposure to second hand smoke during adolescence was linked to hearing loss, based on blood tests for nicotine-related products.
This time they analysed data on a group of 12- to 15-year-olds who underwent hearing tests in 2005-2006 as part of a national health survey, and whose parents were asked about smoking during pregnancy. The hearing exams were done in both ears to see if children had any trouble picking up sounds at different pitches.
Researchers discovered that 16% of teenagers surveyed had been exposed to smoke while in the womb. These teens were three times more likely to have one-sided, low-frequency hearing loss compared to those who were not exposed to cigarette smoke. The level of hearing impairment associated with foetal exposure to tobacco smoke was ‘relatively modest’ at three decibels however an almost three-fold increased odds of unilateral hearing loss in adolescents with prenatal smoke exposure was described as ‘worrisome’.
Weitzman said many teens with mild hearing loss don’t realise they have a problem, but that it can lead to irritability and trouble in school. What’s more, he said it’s possible the mild hearing loss measured in some adolescents will only get worse in adulthood. Hearing researcher Abbey Berg from Pace University in New York said the findings “make sense”, given what is known about risks to the baby when a woman smokes during pregnancy, including reduced oxygen flow.
She also advised that hearing conservation and hearing education should be started at a very young age. Weitzman agreed that it’s important to spot young people with hearing trouble early saying that “Parents might really want to consider having their 12- to 15-year-olds undergo hearing tests if they smoked during pregnancy,” he said.
If you’re worried about you or your child’s hearing contact your local Hidden Hearing branch. Hidden Hearing offers free hearing tests at its 60 branches nationwide. To book a test Freephone 1800 370 000 or visit http://www.hiddenhearing.ie.