One of the cool features available on the Samsung Galaxy S4 is the Air Call Accept feature; with this feature, a call can be answered without the user of the phone touching the handset. To answer a call, the owner of the device merely swipes his hand over the infrared sensor that is next to the earpiece speaker, and the phone will respond appropriately...Source: http://www.phonearena.com/news/Video-shows-off-Samsung-Galaxy-S4s-Air-Call-Accept-for-almost-any-Android-model_id45740
