Importing and Exporting Audio and MIDI : Drag and Drop : Elastic Audio on Import
 
Elastic Audio on Import
When importing any audio file by drag and drop to an Elastic Audio-enabled track, the audio file is imported and analyzed (if not already analyzed). If the imported audio file is tick-based, it is conformed to tempo using the track’s Elastic Audio plug-in. If it is a sample-based audio file, such as a single drum hit or short sound effect, it maintains its original duration. Longer audio files with no detectable tempo also remain sample-based.
When importing audio by drag and drop from Workspace browsers, Mac Finder, or Windows Explorer to empty space in the Edit window, Pro Tools | First creates a new tick-based, Elastic Audio-enabled track.