The VoiceLayer SDK includes several interfaces used for receiving events from various SDK events:

Interface Use
VoiceLayerChannelEventListener Receiving notifications for channel events related to the authenticated user.
VoiceLayerChannelUsersEventListener Receiving notifications for channel events regarding other users in a subscribed channel.
VoiceLayerMessageEventListener Receiving notifications for message post, update, and removal events associated with a subscribed channel.
VoiceLayerUserEventListener Receiving notifications for when a user related to the authenticated user via a channel is updated.
VoiceLayerPlayerEventListener Receiving notifications from the VoiceLayerMessagePlayer when playback has started, stopped, paused, resumed, finished or failed.
VoiceLayerRecorderEventListener Receiving notifications from the VoiceLayerMessageRecorder when recording has started, finished, or failed.