Clips can contain one audio channel (mono), two audio channels—left and right (stereo), or five audio surround channels with a low-frequency effects audio channel (5.1 surround). A sequence can accommodate any combination of clips. However, all the audio is mixed to the track format (mono, stereo, or 5.1 surround) of the master track.
You can determine whether a stereo clip is placed on one or two tracks. Right-click a clip in the Project panel, and select Modify > Audio Channels. If you choose to place a stereo clip across two tracks, the Clip Panners use their default behavior (left to left, right to right).
Premiere Pro lets you change the track format (the grouping of audio channels) in an audio clip. For example, you can apply audio effects differently to the individual channels in a stereo or 5.1 surround clip. You can change the track format in stereo or 5.1 surround clips. In such cases, the audio is placed on separate mono tracks when the clips are added to a sequence.