AudioChannelActivity.kt

    private var channelListener: SoraAudioChannel.Listener = object : SoraAudioChannel.Listener {

        override fun onConnect(channel: SoraAudioChannel) {
            ui?.changeStateText("CONNECTED")
        }

        override fun onClose(channel: SoraAudioChannel) {
            ui?.changeStateText("CLOSED")
            close()
        }

        override fun onError(channel: SoraAudioChannel, reason: SoraErrorReason) {
            ui?.changeStateText("ERROR")
            close()
        }

        override fun onAttendeesCountUpdated(channel: SoraAudioChannel, attendees: ChannelAttendeesCount) {
            Log.d(TAG, "onAttendeesCountUpdated")
        }

    }

    fun start() {

        channel = SoraAudioChannel(
                context           = this,
                signalingEndpoint = Config.SIGNALING_ENDPOINT,
                channelId         = channelName,
                signalingMetadata = "",
                codec             = audioCodec,
                streamType        = streamType,
                listener          = channelListener
        )
        channel!!.connect()
    }

    fun mute() {
        channel?.mute()
    }

    fun stop() {
        channel?.disconnect()
    }