You may put anything you want in your ear as long as it is for hearing protection. So noise canceling earbuds would be ok, but for music or even navigation instructions it would not. There is no way we are getting music allowed, I was asked about that several times, it would be a deal killer. Here is part of the legal analysis provided to the House. There is also a clear exception for 'headphones' that are built into the helmet, you can use those for anything you want.
The bill clarifies that both earphones and earplugs include devices that provide the user either entertainment (radio programs, music, etc.) or hearing protection. As such, under the bill, a person operating a motor vehicle is prohibited from wearing earphones or earplugs, in both ears, for either hearing protection or for entertainment purposes. However, a person operating a motorcycle has the limited, permitted exception of wearing earphones or earplugs for hearing protection.
Full text of the bill, and the legal and financial analysis is here: https://www.legislature.ohio.gov/legislation/legislation-documents?id=GA133-HB-129
Interesting thing I learned reading through these documents, the current law is a minor misdemeanor. Now that is pretty f'd up.