SO!!! Last year we went on a trip and took the DVD player for the kids. At some point we looked back and the foam pieces of the headphone covers were missing. Looked at my 2 year old, and the evidence was in his mouth! He ate them! This was our 3rd pair of "cheap" headphones for the kids, and they are NOT cheap! $5 a pop. They get lost, stepped on, etc. But I was not about to replace these AGAIN!
Searched for some covers to buy or make, and voila! Found these on ravelry.com (my favorite knit and crochet site for patterns!). Was able to make these with some yarn I had on hand and just in time for us to go on vacation. Original pattern by Jennifer Ofenstein, and found on her blog here.