How does the Space Replay record audio? The Space Replay
A hovering object that explores and manipulates transitional public
spaces with particular acoustic properties. By constantly recording
and replaying these ambient sounds, the levitating sphere produces a
delayed echo of human activity.


In this project, the Arduino board and an Adafruit Wave Shield is used. The Wave shield is not designed to record audio however, they say that they use the board for both recording and playback.

The sphere responds sonically to people and its surroundings by means of a battery-powered Arduino, an Adafruit Wave Shield hacked to record and playback audio on-the-fly and a small speaker.

This generates a few questions.

How would this be done?
Where would the microphone be placed inside the balloon for decent audio capture?
Would there be a better way to design this?
It seems to be possible to record with the shield using a library called waverp


  WaveRP is an Arduino library for recording and playing Wave files with
  the Adafruit Wave Shield. It records 8-bit mono files at 4,000 to
  44,100 samples per second.


Some details adafruit blog:


  It records 8-bit mono files at 4,000 to 44,100 samples per second.