Auditory illusions with examples from Daft Punk

Listening to Daft Punk every now and then is a never aging event for me. Their albums have a variety of musical diversity, and you can always enjoy their fairly repetitive songs on boring household activities. ‘One more time, we’re gonna celebrateh! Oh yeah, Don’t stop the washing!’ Well, one of the most influential electronic duos of the millennium had plenty of tricks in their bag to put into their music. Today, I will try to introduce three of them with examples.

What is Psychoacoustics? Link to heading

Psychoacoustics is an area that includes sound perception and audiology. The area studies psychological responses to auditory events, and the field is as extensive as acoustics, psychology, sound and electronic engineering, physics, and biology. The human auditory system is a complex system that starts from our pinna (your visible ear) and continues to the ear canal, membrane, auditory ossicles, cochlea, lateral superior olive, and medial superior olivary and travels in your brain to hear what is vibrating over the air. Everything we experience has a processing time of milliseconds. Perhaps that shows how fast and strong the human brain is. Although we have such a capable auditory system, scientists have shown that our perception may play some tricks when it comes to audio recognition. And by that, I don’t mean the physical mechanism but psychologically induced ones. Those findings show that hearing is also cultural; different cultures may hear differently.

Continuity Effect & Phonemic restoration effect Link to heading

If a sound is interrupted by a noise with enough loudness in a short interval, we tend to hear the sound continuously. One can create gaps less than 200ms in a tone and fill those gaps with a particular noise which will hide the gaps for you. The shortness of duration combined with the noise, our brains tend to hear a continuous sound signal. Phonemic restoration slightly differs from the continuity effect. This time our brain “fills” the gaps of missing sounds. Our brain acts meddlesome in favor of increased intelligibility, even though the sound lacks information. We observe this phenomenon in the popular Daft Punk song: “Harder, Better, Faster, Stronger.” If you start listening around 2:20, you will experience the various cuts. (most noticeable around 2:50)

The Octave Illusion (Deutsch’s Octave Illusion) Link to heading

The Octave Illusion is one of the most interesting psychoacoustic illusions, first discovered by Diana Deutsch in 1973. The illusion works as follows: Two tones, one with higher and one with lower pitch, play in our ears in an alternating fashion visualized as follows:

There is one octave between the tones. If the alternation is short enough, you will hear the higher tone in one ear and the lower in the other. Your handedness plays a role here. Right-handed people tend to hear the higher pitch in the right ear. If you are left-handed or ambidexter your perception may vary. For this illusion, our example comes from the Discovery album. Open the song Aerodynamic and fast-forward to 2:28, start listening to the passage. I hear the higher pitch on my right and the lower one on my left ear. What about you?

Talking Piano Link to heading

This effect is the art of making the piano (or another instrument) speak! There are a number of examples of it, where people approximate human speech by converting it into fundamental frequencies and then playing the piano notes to reconstruct the atomic structures of speech. An interesting example you can find is here. Even though the effect is named a talking piano, other instruments can speak as well. In their song “Robot Rock”, you can hear the guitar chords talking, as if they are singing the lyrics, ehm, Robot Rock!

Conclusion Link to heading

There are more than three auditory illusions to present (maybe more than 40) and Daft Punk may have created songs including those illusions. It is evident that hearing is not just physical but also psychological. Speaking of psychology, does anyone know how do our feelings connect to music? Listening to Instant Crush, Veridis Quo, or Something About Us, you will most likely fall into a brown study. That is a phenomenon I can’t explain myself either.

Until next time,