Great question Angela.
I can tell you I've tried them all.
I'm fair skinned and burn very easily.
My sequence of trial from oldest to most recent is:
I started with cap, block out sunscreen and head phones.
Then modified the cap to add a back of neck cloth like a foreign legion hat and still used headphones.
Then bought a funnel webb hat with cut outs for head phones. Good, but looks a little daggy ...... I'm a little vain and like to look cool, hahaha!
Have now settled on an Indiana style full brimmed hat and earphones. Certainly my preference now. Used this combo in 30+ C heat in FNQ. Worked a treat and looked the part.
However, did try a few different pairs of earphones from a cheap pair from Officeworks to my iPone earphones and eventually settled on a relatively expensive, about $90, Sennheiser earphones. Fortunately my son gave me the Sennheiser's because he upgraded. They work a treat.
Hope this helps.
Cheers