More microphones result in better sound quality and enable the device to filter out background noise.
Parrot Zik Sport: 8
16. has an on-ear form
This device comfortably rests on top of your outer ears. As it doesn't block out everything from the outside world, it's preferred in places like office environments and recommended for outdoor activities.
Beats by Dre urBeats SE
V-Moda True Blood V-80
22% have it
17. has an earbud form
The earbud form is ultracompact and lightweight, with little or no interference with earrings, spectacles, hats, or hairstyles. For some people it is more comfortable than in-ear form.