According to the latest rumor, Apple might remove the 3.5mm headphone jack on the next-generation iPhone and replace it with a Lightning connector.
Coming from Mac Otakara, a reliable source when it comes to Apple devices,
the rumor cites reliable sources claiming that Apple will ditch the 3.5mm headphones jack and go with a slimmer Lightning connector. The same source also suggests that Apple will also release Lightning-based headphones.
In order to support earlier 3.5mm headphones, Apple will have to implement a digital-to-analog converter (DAC) that will offer backward compatibility as well as come up with a 3.5mm to Lightning adapter.
The lack of a 3.5mm jack could also make the next-generation iPhone a bit thinner.
Source:
MacRumors.com