I have noticed that in business class on some airlines (Lufthansa and Finnair, specifically), the headphone jack has 3 holes. This set-up makes it impossible for me to use my own headphones (I have Shure noise-reducing earbuds that I really enjoy). Anybody know if there's a 3-prong adapter available somewhere? I have a 2-prong adapter that has served me well in the past.

Thanks for any help you can provide!