That's nearly 47,600 people, according to a recent study seeking to estimate the condition's prevalence.
The intrigue: Hearing loss is more common in rural areas, per the study.
It's unclear why, but age and exposure to factory or farming equipment could contribute.
Zoom in: Johnson and Story counties had fewer than 8% of residents with hearing loss, the lowest estimated rates in the state. Both places are college towns.
Audubon and Dickinson counties had estimates of just over 20%, the highest rates.