Fun auditory illusions, part deux

Last week, I posted about auditory illusions featured on New Scientist's Web site. In the discussion following the post, several readers commented on the pioneering work in this area by UC San Diego psychology professor Diana Deutsch. She's been researching auditory illusions for decades and even curated two CDs of examples, "Musical Illusions and Paradoxes" and "Phantom Words and Other Curiosities." Deutsch's research page provides samples of some of those illusions. From her site:

 Psychology Imgs Fig07

Here we describe and illustrate some of Deutsch’s musical illusions and paradoxes. They show that people can differ strikingly in the way they hear very simple musical patterns. These disagreements do not reflect variations in musical ability or training. Even the finest musicians, on listening to the stereo illusions described here, may disagree completely as to whether a high tone is being played to their right ear or to their left. And the most expert musicians, on listening to the tritone paradox, can engage in long arguments as to whether a pattern of only two tones is moving up or down in pitch.

How do we explain these striking perceptual discrepancies? In the case of the stereo illusions, disagreements tend to arise between righthanders and lefthanders, indicating that they reflect variations in brain organization. In contrast, the way the tritone paradox is perceived varies with the geographical region in which listener grew up, so differences here are related to the languages or dialects to which people are exposed.

The illusions and paradoxes described here lead us to wonder what other curiosities of music perception might exist that have not yet been discovered. But using the principles that generate these illusions, we can now produce music that sounds radically different from one listener to another, and even from one audience to another.


Previously on BB:
• Fun auditory illusions Link (Thanks to the commenters and Tim Carr!)