This linked article shows how ages are changing in every state. It includes data by race and ethnicity, too. Of course, this affects radio as Nielsen samples in proportion to population cells.

mediaconfidential.blogspot.com
One quote; “As the nation’s median age creeps closer to 40, you can really see how the aging of baby boomers, and now their children — sometimes called echo boomers — is impacting the median age. The eldest of the echo boomers have started to reach or exceed the nation’s median age of 38.9,” said Kristie Wilder, a demographer in the Census Bureau’s Population Division."
(No paywall)

New Population Estimates Highlight Increase in National Median Age
The nation’s median age increased by 0.2 years to 38.9 years between 2021 and 2022, according to Vintage 2022 Population Estimates released...
One quote; “As the nation’s median age creeps closer to 40, you can really see how the aging of baby boomers, and now their children — sometimes called echo boomers — is impacting the median age. The eldest of the echo boomers have started to reach or exceed the nation’s median age of 38.9,” said Kristie Wilder, a demographer in the Census Bureau’s Population Division."
(No paywall)