“Morality,” Radiolab (Episode 3, Season 2)
The following is organized in sections of time per minute:

• 00:58 – 01:15
  Jad explains that the morality problem takes place on a train track, and immediately, sounds of a train begin in the background. As Jad continues to explain the problem, the volume of the train audio increases, seemingly getting closer and closer. This is a great example of illustrative audio that paints not only an auditory but also a visual picture for the listener.
• 03:44 – 03:46
  It lasts only a second, but here there are two audio fragments playing at the same time. Radiolab uses an audio fragment from an interview and use the natural pacing from the interviewee (something unplanned) and then record Jad, the co-host, duplicating the natural pacing (something planned and controlled).
• 04:35 – 04:47
  While Robert is describing Josh Green in vivid description, the background noise/audio is a recording of someone walking in to meet the subject. This is a common occurrence on Radiolab that creates the feel for the listener that the interviewee is seemingly being interviewed in present tense and allows them to slowly shift their attention from Robert to the interviewee, here Josh Green.
• 05:44 – 06:35
  This small anecdote as told by Josh Green is a great piece of audio for two reasons. Sure, it’s interesting enough; but what really makes this great is that the listener can hear the humor in Green’s voice, which then makes them feel like they better know (and will better trust the information from) Green.

Radiolab is a podcast from WYNC Studios. Episodes can be found for free on iTunes or Radiolab’s website. Radiolab can be heard on 89.3 WFPL on Saturdays at 4 PM.