About 50-50, but the ear they fall out of varies even at the same task, suggesting that my ear cannals change shape (allergies?) just enough to make a difference.
Yes, those or the ones ComeToTheDarkSideWeHaveCookies mentioned. I agree that they do a wonderful job at eliminating ambient noise–personally I would use them jogging, but not for driving. Where they really changed my life, however, was when flying. Crying babies? Like I could care. 
Well earbuds don’t stay very well in my ears either b/c I have atresia/ stenosis…basicly nonexistant ear canals and what little ear canals there are are very small. From what my ENT said, my earcanals are the size of a three year olds. Does everyone in this thread go “deaf” when they have a cold?
So buy me a set, too! Now you’re up to $5.98!
For those suggesting the ones that hook over the ears - they also suck. I wear glasses and I can’t use them and see at the same time.
I ended up getting these which are “traditional” headphones (pads) but don’t have the 1-piece head band. They clip over the ears.
Earbuds, earbuds with clips and 1-piece headphones don’t work for me because:
- I have stupid ear canals
- I have stupid ears
- I have a fat head
I’ve always attributed the stupidity of my ear canals to me having TMJD which mucks up the positioning of the bones and cartilidge in that area. One of the tests the TMJD dentist does is puts his pinkies in your ears and asks you to open wide. If it hurts, you’re still out of alignment.
Although…Ginger is right - the over-the-ear clips are hard to keep on with glasses, but having the full pad of sound instead of a bud gives you a better chance at hearing something if they are not perfectly centered.