Stereo Headset and Adapter No In-Game chat?

If you are talking about the Chat headset, that comes with Xbox One, then No. If you are talking about Stereo Headset, with an Stereo Headset Adapter. then Yes. Using the Stereo Headset Adapter give to both Chat and Game sound to the headset. If you TV,
is connected to the Xbox, your TV sound, will go to the headset.

Hi there,

What is the specific headset you are plugging into the adapter?

Headset's, headphones, or earbuds with stereo sound will have the ability to have game audio along with chat volume that is adjusted with the adapter or in the "Audio" settings that will only appear when plugging into the 3.5mm port which you have confirmed
was the issue with the original controller.

There are some headsets however that do not have stereo sound and are strictly only meant to chat with others, and are usually referred to as chat headsets. These tend to only have one earpiece whereas stereo headsets will have two.

If you have a stereo headset/headphones plugged into the adapter, then the chat mixer slider that is usually found in the "Audio" settings will be controlled on the adapter with the game controller icon button indicating the game audio volume and the button
with the icon of a person indicates the chat audio volume.

Same issue with iPhone headset. Audio works great, in party chat, others here high pitch whistle. While less than desirable, it may be that the adapter is not designed to work with inline mic's. Look at the last item in the list below. "Any 3.5mm stereo
headset (that uses the CTIA plug standard) can get stereo game audio by plugging into the adapter"

I hope that the headset can work.

From XBOX.COM Headset Adapter page:

For game audio:

- Legacy gaming headsets get game audio from the back of the console from the S/PDIF port or from your TV/receiver with RCA cables. Get chat audio by connecting the 2.5mm chat cable to the adapter

- New Xbox One headsets – get chat and stereo directly from the adapter. No need to connect anything to the console

- Any 3.5mm stereo headset (that uses the CTIA plug standard) can get stereo game audio by plugging into the adapter

Xbox One Stereo headset
www.xbox.com/.../stereo-headset

The mic that came with the Xbox one works. My adapter chat button makes the game volume higher. Is it suppose to be like that?

•Some third-party products come with a stereo headset adapter that may look different from the Xbox One Stereo Headset Adapter made by Microsoft, but they all function the same way.

•You can only connect an Xbox 360 Chat Headset using the stereo headset adapter with a 2.5-mm to 3.5-mm converter, which comes with the Xbox One Stereo Headset Adapter. The Xbox One Stereo Headset does not include this adapter cable.

support.xbox.com/.../connect-compatible-headset