You can preview audio and MIDI clips and clip groups in the Clip List. Previewing follows the master Audition path as selected in the Output page of the I/O Setup. The base level for previewing is determined by the Master Fader (or Auxiliary Input) level assigned to the Audition path.
Sample-based clips play back at their native tempo. Tick-based MIDI and Elastic Audio processed clips play back at the session tempo (based on the location of the playback cursor). You can also preview clips from the Clip List during session playback.