Listening to the sine-wave speech sound again produces a very
different percept of a fully intelligible spoken sentence. This
dramatic change in perception is an example of “perceptual insight” or
pop-out. We have argued that this form of pop-out is an example of a
top-down perceptual process produced by higher-level knowledge and
expectations concerning sounds that can potentially be heard as speech:

There are audio samples at their website which demonstrate this.  It’s really neat to hack your perception.