A quick demo that makes use of AudioClip array, audio.clip and Random.Range() to randomise the audio asset file that is played back when an event is triggered.
In short, the process is:
• Find an in-game object that currently triggers a single sound
• Find the script that is associated with that object that triggers that sound
• Define a new variable at the start of that script to create an array of audio clips, e.g. var RandomSounds: AudioClip;
• Find a reference to audio.Play(); within the script
• Randomise the selection of the audio clip in the line before audio.Play(); e.g. audio.clip = RandomSounds[Random.Range(0,RandomSounds.length)];
• Save the script and run the game again