Apple had a couple of new patent applications published by the USPTO today (spotted by AppleInsider), including one detailing how internal fans could be made to fit mobile devices to help dissipate heat, and another for headphones that become speakers for when listening goes from private to shared scenarios, which even describes how in-ear models could work that way.
The patent for internal fans includes a design that combines device physical feedback along with cooling powers to save space compared to when those components are separate. In one permutation, there’s also a design for taking air in through existing holes like a headphone or connector port, and expelling excess heat through the same mechanism. That would also help with space-saving efforts.
In terms of its likelihood for actual use, I’d guess that it probably won’t be employed in a shipping product, but instead represents one line of Apple’s thinking about how to cool mobile devices, but not the one they ended up spending much time on. The more logical path seems to have been to work on processor efficiency, which Apple is clearly committed to with its in-house processor design and engineering efforts.
Headphones that do double duty as external speakers is a much more practical and likely invention, looking at Apple’s product release history. It describes methods for turning both external on-ear type headphones into speakers with rotating ear cups, and ways to make even in-ear headphones like Apple’s own EarPods into speakers powerful enough for multiple people to enjoy. The headphones in all cases can detect their orientation, and even their proximity to a user’s ear to determine in which mode they should be operating.
Apple is clearly still interested in evolving its headphone design, since in introduced the new EarPods alongside the iPhone 5. And external speakers for iOS devices are consistently strong performers in terms of accessory categories. The main concern would be quality: making drivers small enough but powerful enough to sound good at any decent volume would be a significant engineering challenge.