In New York, a man's average hearing age is more than 12 years older than his actual age; in Houston it's almost 13 years older; and in Los Angeles it's over 14 years.

That shows the measurable impact of noise pollution on hearing.

But noise damages more than men's hearing.

According to a recent study, even relatively low levels of sound can make men infertile — yes, you heard that right — especially when noise repeatedly disturbs sleep.

Looking at eight years of health insurance data on more than 200,000 men ages 20 to 59, the researchers identified 3,293 men who were diagnosed with infertility. They then calculated an individual's level of noise exposure by cross-referencing ZIP codes with info from the National Noise Information System.

What did the guys have in common? They all were exposed to noise levels above 55 decibels (dBs) night after night.

(Air conditioners come in around 60 dBs; a passing diesel truck emits 85 dBs and an emergency vehicle's siren hits 115 dBs.)

So how can you keep noise from messing with your sleep cycle and your fertility?

• Download a smartphone decibel checker; test nighttime sound levels in your bedroom.

• Check if digital devices or appliances in your home exceed 55 dBs. If they do, turn them down (or off), or trade them in for quieter models.

• Install double- or triple-pane windows; seal window frames with stripping. Use double-hung, extra-heavy curtain fabric.

• Sleep with earplugs. (Discard foam plugs daily, and clean reusable plugs regularly.)