Channel Control Area

The channel control area to the left of the waveform in the Audio Editor allows you to select channels, and to mute and solo single channels of multichannel audio files.
Figure 1. Channel control area of a stereo audio file
Figure 2. Channel control area for channel clusters of a multichannel audio file
Mute

Mutes the channel cluster. This only affects playback, not rendering.

Solo

Solos the channel cluster. This only affects playback, not rendering.

Fold/Unfold Channel Cluster

Switches from expanding to reducing the space for individual channel clusters, and vice versa.