Sonos One pair which speaker should Alexa voice come out from?

This just started happening to me after the last firmware update.

The Amazon server will select the Alexa device that has received the strongest and clearest voice command and then duck the other devices. Only the triggered device will respond. Are you saying you are getting a response from both Sonos One's?

Yes, but out of sync.

I suggest you Disable and then Enable the Sonos skill within the Alexa App and retest.

Tried that and still it goes bing bing with a delay bewteen the pair of speakers.

Okay, please try the steps I've listed in the Answer to this post:

https://en.community.sonos.com/amazon-alexa-and-sonos-229102/sonos-one-not-responding-to-alexa-comands-6793239

I’ve found it easiest just to enable Alexa on one of the devices in the pair. That way it’s predictable which speaker responds, and it avoids the problem of sometimes setting off both.

Occasionally, I'll speak quietly to the Sonos One near my desk which is less than four feet away and I'll hear the wake sound from that and one or two other Sonos Ones in distant rooms with a small delay. Sometimes it's the one furthest away that actually responds to the subsequent command. This wasn't an issue until the 8.2.3 update, which significantly increased their responsiveness. Not a major issue for me, but this does seem need a little further tweaking so it works properly. Of course, if I were able to disable the wake Sound on the Sonos One .... :D

FWIW, I don't remember this happening between the two speakers I've paired in the living room, but it's possible. I had thought about disabling Alexa on one of them, but so far it hasn't been necessary.

I suppose in a stereo pair you could turn the mic off on one of the Sonos Ones.

The way it should be working, the Sonos One that has the best response in quality of hearing and time to the Alexa servers should be the one to reply. You might each the chime from any One that hears you, but only the one that "wins arbitration" should reply back with your command. If you find multiple Sonos Ones are replying to the same question, not just the chime but the full Alexa reply, there may be something up with the device registration, and UKMedia's suggestions are a good start. De-registering the devices and setting voice services up again is a good way to make sure they're on the same account. If one player is linked to a different Amazon account this could happen.