We have been seeing pictures of Apple's Lightning EarPods for a while now, the same ones that will supposedly be shipped with the iPhone 7 that will supposedly come without a headphone jack.
The video below by Mobile Fun, UK's largest online mobile accessory retailer, shows a working pair of Lightning EarPods. The design seems consistent with Apple's current EarPods. The major differences are of course a Lightning connector instead of a standard 3.5mm TRRRS connector. The remote module is also bigger, most likely to house the DAC/amp if the Lightning EarPods use a digital connection. The speakers look identical so it's unlike the sound is going to change in any way.
There are questions regarding whether Apple is going to ship these with the phone but if Apple does remove the headphone jack, which it now seems it will, it's highly likely the Lightning EarPods will come with the phone as the iPhone has always shipped with a pair of earphones inside the box. It's unlike we will see an adapter though, the kind that comes with Motorola or LeEco phones without a headphone jack. Apple would want to sell you that separately.