Last June Apple announced the capability to plug headphones and other accessories into the iPhone and iPad Lightning port and in 2015 we expect to see the first Lightning headphones arrive from a variety of companies.
With Lightning headphones the iPhone can send higher-quality lossless stereo 48 kHz digital audio to your ears and include a microphone that picks up mono 48 kHz digital audio. Noise cancelling headphones can also grab power from your iPhone using this port.
The Philips Fidelio NC1L are the first active noise cancelling headphones without batteries thanks to this connection. These arrive in April for $299.