Background:
When connected to an Echo type channel, user speech will be sent to Vivox servers, then transmit back to the local client and played out of the user's selected output device—in other words, "echoing" back spoken audio.
This is separate from local audio capture with "loopback" rendering, which echos back audio instantly and does not require a network connection. Local loopback is only available in the Vivox Core SDK.
Note: Echo channels are a special type of channel where the local user is the only participant. Even if two users join "the same" echo channel—the connected channel has the same name and domain—the two users will not be able to hear each other.
Scenario 1:
Echo channels can be used by developers for quick iteration when implementing Vivox during evaluation or development. For example, a solo developer can test out Vivox channel connections or perform quick debugging during development by joining an Echo channel to verify the connection success and quality of voice chat.
Scenario 2:
Echo channels can also be used by players as an effective troubleshooting tool when implemented as a "mic check" feature in a voice chat settings menu. For example, a user might want to verify their input and output device selection, or use the echo to adjust volume settings. It also validates that the user is able to connect to Vivox audio servers and roughly demonstrates the delay of an audio round trip to Vivox servers.