Google: The Pixel 2's USB-C Port Is Its Headphone Jack
 

Per Google Community Manager "Orrin": "The Pixel 2 still comes with a headphone jack, but we have moved to USB-C, a standard that is becoming commonplace in the best phones and laptops of today. Moving to the USB-C audio port with Pixel 2 allows us to provide a better audio and digital experience, as we move towards a bezel-less future." We realize that some of you might be looking for USB-C headphones, and we want to provide some guidance around headphone compatibility with Pixel 2 devices. The main thing to keep in mind is that Pixel 2 devices are compatible with USB-C headphones that support digital audio.

http://www.hardocp.com/news/2017/10/...eadphone_jack/