The most useful touch sensor function is in my opinion the playback control. The second most useful one is the ambient sound control. Therefore, why can't we select touch sensor control differently for when only using one earbud?
When only using one earbud, let user specify control, for example playback control. When using both, then it makes sense to specify what should be on the right and what should be on the left.
The background is that many times I only use one earbud, for example when listening to podcasts while cycling. This way, I can hear the traffic around me. Or I can do the dishes and listen to audiobooks while keeping an ear out for the sound of kids crying in the living room. When I use two earbuds, it's great to have the ambient sound control too, but if I have to choose, I prefer playback control no matter which single earbud I use. Which earbud is most suitable to use changes, one might low on battery, I might want to keep the ear closest to whatever I need to be aware of free while listening on the other.
