A Google search on “Does driving with windows down cause hearing loss?” yields some pretty definitive YES results.
A 2010 study of just the wind/road noise in top-down/windows-down convertibles showed the average noise level to be 89 dB. Playing the radio loud as I did would certainly jack things up a bit more.
The chart in the following Johns Hopkins article on preventing noise-induced hearing loss rates the sound level caused by driving at high speeds with the windows down as being in the 85 to 95 dB range. So, Yep, with the radio blaring away, and driving 4 to 6 hours each way on a trip as I did, I bet that I suffered a bit of hearing loss from that proclivity over the years. I enjoyed a great “feel of the open road” experience, though!
https://www.hopkinsmedicine.org/international/_downloads/Hearing_Loss_JHI.pdf