Noisy suburban streets significantly reduce men’s fertility, new research reveals. Researchers believe night-time noise disturbs sleep, leading to male infertility. Previous research revealed getting less than six hours of sleep a night reduces a man’s chance of getting a woman pregnant by 43 percent. This is thought to be due to a lack of shut eye being associated with a lowered sperm count, altered sperm shape and reduced testosterone levels.

Infertility problems affect around one in six couples globally at least once in their lifetime, either temporarily or permanently.

Researchers from Seoul National University analyzed 206,492 men aged between 20 and 59 from 2006 to 2013. They calculated noise levels using information from the National Noise Information System combined with the study’s participants postcodes. Of the participants, 3,293 were diagnosed with infertility during the study.

Results, published in the journal Environmental Pollution, revealed that night-time exposure to a noise level of 55 dB – the equivalent of a suburban street – significantly increases a man’s likelihood of being diagnosed with infertility.