I listen to music on headphones while my wife watched TV. In different circumstances she might use the headphones letting me have the speakers.

What confuses me is that it seems like listening to the TV on headphones would use the Arc, if I had one, so it could not be used to listen music because it is being used to transmit sound to the Ace.

Got it in one. They are just BT headphones.

Will you just stop!!?  People are asking for serious answers and all you do is offer up sarcasm and stupidity.  Just let people answer the questions.  Trust me, it won’t take away from your 5,372 sarcastic comments in other threads (as if anything could).  Your insistence on injecting your stale humor into every thread is childish and tiresome. 

It certainly seems that way.

I personally see no reason why I would want to group the headphones with other rooms to play music, since headphones by their very nature are a singular experience, and follow you from room to room anyway.  I do see the capability to group headphones with a soundbar to play at the same time as an answer to those who have trouble hearing and yet want to watch TV with others in the room who have no disability. 

Another use case (one I can give no first hand knowledge of) that some have asked for is playing music while playing video games.  There are those who don’t like the Autoplay feature when playing games because they prefer background music to the game audio (that’s if I understand it right.  I could be wrong). 

You won’t be able to listen to headphones and the Arc at the same time though.  While I agree this would be a nice feature, it isn’t going to be available, and least anytime soon.

Along the same lines, this would be useful if someone was watching TV outside of the atmos audio sweet spot, such as a side chair or something, while others were in the sweet spot.  The side chair person could hear proper atmos through headphones.

My use where I would want to be playing TV audio through soundbar  while headphones play music is in my gameroom/home office.   There are times where kids are playing video games that I don’t want to hear, and I’d like to listen to music instead.  In this case though, I would need to use bluetooth audio for the music, since Ace can’t directly get wifi audio...and because the soundbar in that room is a Beam 2. Honestly, if no one was using TV audio at the time, I may still opt for headphones as the desk is not in the atmos sweet spot, and I would like to easily switch to computer audio or phone audio when needed.

Not the end of the world, but a feature I was looking forward to.

Both of those make some sense. 

With my hearing issues I was really hoping for both the ability to work with the Arc (both playing) and individual channel volume controls so I could boost the center channel.

I don’t think you could call two speakers (right ear, left ear) ‘proper’ Atmos, by definition. 

Given the audio magic you can pull off with a DSP I’d not be surprised to hear a set of single speaker headphones being able to fake surround sound.

Keep in mind your ear doesn’t hear multiple speakers or directions, it just processes the sound entering your ear canal and that can be tweaked to imitate about anything.

It’s amazing what Apple did with Airpod Pros. Have every confidence in Sonos. 

I have an actual real world requirement for this functionality.

I have an open plan kitchen, lounge & dining space and when I turn on the extractor fan in the kitchen I can still see the TV but I can't hear it. Now when I’m by myself its not a major problem because I can just turn on up the ARC so that I can hear it but when my wife is in the lounge it is far to loud to have the ARC turned up so I can hear it. It would be great if my wife could continue to watch that TV with the arc at a comfortable level and I could wear the headphones to listen while I have the extractor on in the kitchen.

For me while I like hearing music through speakers headsets have always presented a more intimate experience. Even back before surround sound was a thing (or even quad for that matter) headsets always (IMO) brought the music to you. I can remember the thrill of actually hearing the needle on a turntable as it started its trek through the grooves of a record in the first few seconds of play.

I’m especially excited about the ability of the Sonos Arc (and later the Beam 2) to transfer/send Dolby Atmos audio to the Sonos Ace headset. They will (per Sonos marketing) offer the Dolby Atmos experience with dynamic head tracking. That said one should be surrounded in hyperrealistic sound from every direction. 

Not hijack this thread but if you are so inclined click the link below to offer your opinion on my thoughts as I have pre-ordered the Sonos Ace headset.

I really like to feel the low end of my music so headphones have always been “nice but only when needed” sound source.

I’m really not a Bluetooth fan and having to have my Arc running to listen to the headphones would aggravating as we almost always have our media room system powered down for weeks at a time.

A Beam 2 would be an option but I already have one too many Beam 1s so adding another would get spousal aggravation into that option.

For now I’d have to say a used newer / S2 Connect, a headphone preamp and wired headphone looks to be my best option, one I’ve rejected on value and use time for some time now.

Here are a couple of scenarios I would use:

• It’s a weekend and we have music playing in the house. I go out to the garage to work on something, or into the garden to do some gardening. I want to keep listening to the same music that’s playing in the house, so I put the headphones on, join them to the group and away I go. When I come into the house I just take them off and I’m still hearing the same music. Currently I use the Roam for this scenario, but it’s awkward to carry it around and I can’t hear it if I’m using a loud power tool.
• I’m cleaning the house. I like to blast music or a podcast all around the house when I clean. But when I start vacuuming I can’t hear it well, so I put the headphones on. Once I finish vacuuming I take off the headphones and keep listening to the speakers. Yes, I could just wear the headphones for the whole time, but maybe there’s some other people in the house who want to listen, or maybe I just don’t find wearing headphones for a long time that pleasant.
• My partner and I are listening to music in the same room. She is hard of hearing and I don’t want the music too loud, so she uses the headphones while I keep listening to the speakers on a low volume.

These are legitimate use cases for me. But admittedly they are niche, and I probably wouldn't spent $AUD700 to get them.

You wear headphones to listen to something you like, like a story or music, while still being able to hear what's happening around you. It helps you focus on your favorite thing in a busy place.