detect, during an audio communications session between a first user device and a second user device, a change event at a first earphones device associated with the first user device, the first earphones device comprising first and second earphones; and

signal the detected change event to the second user device and/or a second audio output device associated with the second user device with modifying, or causing modification of, spatialized audio content transmitted with the first user device to the second user device to become stereo content, wherein the spatialized audio content comprises a first first audio object channel representing a configured to be perceived from a first direction and a second channel representing at least one of: ambience configured to be perceived from a range of directions, or a second audio object configured to be perceived from a second direction, wherein the stereo content comprises first and second monaural channels configured to be output with respective ones of first and second earphones of the second audio output device, wherein the second audio output device comprises a second earphones device.