I briefly took a closer look at the Playbar here on Digitec. You can only operate it like Optical Toslink, i.e. the Sony MDR-HW700DS headphone base station is simply connected in between. So you take the optical cable out of the Sonos and put it in the Sony, then connect it to the Sonos with a new optical cable. This way you can hear the sound on both devices at the same time. To continue watching, you only have to turn down the sound on the Sonos or switch off the Playbar completely. The headphone remote control is in the right ear cup, so everything is wirelessly controllable.