We have put together an amazing list of sound illusions (auditory illusions). In these illusions, your mind can interpret sounds differently from how they are presented. To get the most out of this list, you should have a set of stereo headphones or a stereo sound system with speakers set at a distance, but headphones are preferred. Laptop speakers are not suitable for most of these illusions. So, without any further delay, here we look at the top 37 audio illusions:
37. Tick Tock Illusion
A constant stream of identical clicks can begin to resemble a clock going “tick tock.” You might perceive every second click as louder, even if the recording gives each one equal emphasis.
Psychologists refer to this as subjective rhythmization. The video presents a steady metronome with no accented beat, so take a moment and notice whether your brain arranges the clicks into a pattern of its own.
36. Illusory Discontinuity
The continuity illusion is capable of operating in the reverse direction as well. A tone can appear to halt when another sound cuts across it, even though that tone continues playing beneath the interruption.
While the noise bursts occur in the video, pay attention to the tone. Certain listeners perceive a gap where there is none at all, while others are able to track the tone straight through it. This serves as a reminder that not every listener experiences these effects in precisely the same manner.
35. Hearing with the Third Ear
Naturally, no third ear comes into play here. This name was coined by researchers for a stereo phenomenon where, upon comparing the signals in your two ears, a melody arises from a blend of steady tones.
Slight differences between the left and right channels cause individual notes to emerge one after another. Try listening with both sides of your headphones, then with just one side alone. The melody hinges on how the two signals relate to each other.
34. Combination Tones
When you hear two high notes played at the same time, you might also pick up on a noticeably lower note. People refer to this additional sound as a combination tone. Because it can be very faint, listening in a quiet environment makes it easier to detect.
Certain combination tones come about because of how the ear reacts to sound. Distortion can likewise be generated by audio equipment, which means a low tone does not always originate from the same place. In the video, the effect is shown using two notes.
33. Rhythmic Illusion
A beat can appear to shift when the surrounding music gives you a different sense of where the count starts. You may tap along with an opening pattern, and then, as the other instruments come in, you realize the rhythm has moved beneath you.
Using musical examples, the video demonstrates how a single passage can be heard in more than one way. There is no need for anyone to alter the tempo. A fresh accent or a different feeling for the downbeat is all it takes.
32. Backwards Messages
If you play a song in reverse, you might catch what seems to be a concealed phrase. Frequently, the words become far more obvious once someone points out what to listen for. Until then, that same passage can simply come across as jumbled singing.
This illustrates auditory pareidolia: detecting a familiar pattern within an ambiguous sound. Certain recordings genuinely hold messages that were reversed on purpose, so the direction by itself cannot reveal whether one was intended.
31. Brainstorm or Green Needle
When a toy speaks the word “Brainstorm,” certain people instead perceive “Green Needle.” If you say the two phrases aloud yourself, they sound quite distinct – which is exactly why the effect seems so bizarre.
Try holding one phrase in your mind before the clip starts, then play it again while focusing on the other. Nothing about the recording changes. What you expect to hear can nudge the balance one way or the other, although not everyone is able to flip between the two.
30. Yanny or Laurel
Back in 2018, this brief clip gave the internet a fresh excuse to start arguing. Certain listeners picked up “Yanny,” whereas others were convinced the voice was saying “Laurel.” The recording itself was originally of the word “Laurel.”
The audio holds cues capable of backing up more than one interpretation. What you notice can be shaped by your hearing, the device you play it on, and the frequencies that get emphasized during playback. You might never win over the person sitting right beside you.
29. Talking Piano
A piano may not have a voice, yet it can pull off a respectable imitation. Here, a computer converts the shifting frequencies of speech into a fast sequence of piano notes. If you listen carefully, you might pick out words in what comes out.
The notes trace patterns present in the voice, and being aware of the original phrase helps your brain interpret them. The sound is strange, sitting somewhere between a piano drill and a robot with real determination.
28. Sine Wave Speech
At first, this recording might come across as whistles or electronic chirps. In reality, it comes from speech that has been reduced to a few shifting tones, which track some of the changing frequencies of a voice.
As soon as you realize a voice is concealed within it, those same sounds can begin to sound like words. Certain versions also play the clear speech, which makes the shift even easier to detect once you go back to the odd version.
27. Ventriloquist Illusion
A puppet’s moving mouth can convince you that the voice is coming from it, even when the person next to it is actually speaking. This same illusion can be produced with basic sounds and shapes that move on a screen.
In this university demo, keep your eyes on the ball as you listen through stereo headphones. After that, shut your eyes and repeat the exercise. When you can see the action, the sound may appear to originate from somewhere else.
26. Precedence Effect
When you’re in a room that’s full of echoes, what you generally perceive is a single speaker rather than a multitude of duplicate voices. Your sense of hearing places particular emphasis on the sound that reaches you first, and it usually blends that with reflections arriving just afterward.
The video surrounds a voice with echoes in order to demonstrate how this process unfolds. Thanks to this effect, you can identify where a sound originated, even when reflections come at you from various other directions.
25. Franssen Effect
A tone starts up on one side of the room, and you respond by pointing in that direction. While it keeps going, the sound gradually dies away from that speaker and rises from a different one. You might still perceive the sound as coming from the first side, even once the switch has happened.
When a sound begins, it hands your brain a powerful hint about where it is located. For this demonstration, you will need two distinct stereo speakers, so hold off on it until a moment when headphones are not in use.
24. Chromatic Illusion
The scale illusion mentioned earlier in this list has a near relative in this one. It relies on a chromatic scale that steps through every semitone, with the notes alternating between the two stereo channels.
Rather than picking up a scrambled set of jumps in each ear, a lot of listeners perceive a smooth upper line on one side and a lower line on the other. Put on headphones and listen, then switch them around to check whether the lines appear to shift.
23. Cambiata Illusion
As this recording plays, the notes seem to leap from one ear to the other, yet you might instead pick out two distinct melodies: one higher on a single side and one lower on the opposite side. This pattern goes by the name of the Cambiata illusion.
While it is playing, try switching your headphones around. Even after the channels have swapped positions, some listeners continue to hear the higher melody in the same ear. Others perceive a more involved blend of sounds, and that is part of what makes it enjoyable.
22. Glissando Illusion
This is a sound that appears to move around the room. A gliding tone and a constant oboe note alternate between two speakers. A lot of listeners perceive the gliding tone as one sound that travels smoothly through space.
Diana Deutsch discovered that listeners can perceive its path as going in different directions. For this demonstration, you’ll need two separate stereo speakers. For the original demonstration, headphones work less well.
21. Zwicker Tone
Once a short burst of specially shaped noise comes to an end, certain listeners perceive a faint tone that was never actually played by itself. It lingers for a moment and then dies away, somewhat like an afterimage, but for your ears.
This phenomenon is known as the Zwicker tone. The video offers several examples, so pay close attention each time a burst finishes. Set the volume to a comfortable level; the effect is subtle, and not everyone will hear it the same way.
20. Auditory Streaming
A fast sequence of high and low beeps may come across as a single galloping rhythm. If you keep listening, those very notes might break apart into two distinct streams, one high and one low.
For your perception to shift, nothing in the recording needs to change. Your brain’s grouping of the sounds can shift even as the pattern continues. Try focusing on only the high notes first, and then on the low ones.
19. Auditory Continuity Illusion
A beeping sound cuts in and out, with sudden bursts of noise filling the pauses. Even so, the beep may appear to continue beneath the noise, as though someone had merely masked it briefly.
Pay attention to the softer and the louder noise in the video. Once the noise is loud enough to conceal a possible gap, your brain can perceive the broken tone as a single continuous sound.
18. Phonemic Restoration
When someone is speaking, your brain has a knack for filling in what’s missing. In this demonstration, noise takes the place of portions of speech. You might still perceive the word as though nothing were absent, even when a sound is missing.
Now compare that with a version in which silence fills the gap left by the missing sound. That gap is usually far more obvious. Your ears get a helpful nudge from context.
17. Huggins Pitch
Initially, what you hear seems like nothing more than a blur of sound. Put on stereo headphones and listen carefully for a quiet tone concealed within it. Remove one earphone, and the tone ought to become considerably more difficult to detect.
Both ears pick up nearly identical noise, with a slight variation in one portion of the signal. That variation is what your brain relies on to create the sensation of a pitch. This effect can be faint, so try it somewhere quiet and at a volume that feels comfortable.
16. Binaural Beats
If you play a constant tone in one ear and a marginally different tone in the other, you might perceive a soft pulsing sound. That pulse is not something either ear picks up by itself. The beat emerges once your hearing system combines the two signals.
To try the demonstration, you’ll need stereo headphones. Briefly remove one earphone: the pulsing ought to vanish. Place it back on and listen once more for the beat.
15. Missing Fundamental
Small speakers are able to give you the impression of a bass note that they aren’t really playing. They generate higher tones tied to that low note, and your ear can identify the pitch implied by the gaps between them.
This phenomenon is known as the missing fundamental. In the video, the higher tones are played simultaneously so you can compare the outcome against the low note. For speakers that have very little bass of their own, this is a useful trick.
14. Mysterious Melody
It can be surprisingly difficult to recognize a familiar tune when its notes are spread out across different octaves. The rhythm remains intact, and the notes keep the same names, yet the leaps make the melody come across as a jumble.
Give it a listen before the answer is revealed. After that, have another go at the scrambled version. Once the tune is familiar to you, identifying it can get a lot easier.
13. Octave Illusion
For this one, you’ll want to put your headphones on. Two notes—one high, one low—keep alternating between your ears. A lot of people hear a high note in one ear and a low note in the other, rather than hearing both pitches switch sides.
Now try turning your headphones around. The high note might still seem to come from the same side of your head. Diana Deutsch uncovered this effect, and how it plays out can vary considerably from one listener to the next.
12. Phantom Words
Place two speakers, one on each side of you, and play this recording in stereo. Brief sounds come from both sides repeatedly, though their timing is staggered. Soon enough, you might begin to hear words or phrases that a different listener cannot discern at all.
Diana Deutsch discovered that listeners frequently perceive different things in the very same recording. Allow a bit of time, and the words you perceive may shift as well. For this particular exercise, speakers prove more effective than headphones.
11. Speech to Song Illusion
If you listen to the same brief fragment of a sentence again and again, it can begin to sound like a melody. The recording never changes to a singer. Each time, your ears are receiving the very same words.
Psychologist Diana Deutsch stumbled upon the effect while listening to a recording of her own voice. Once it has repeated several times, you might catch yourself hearing a melody in the way her voice rises and falls.
10. Tritone Paradox
This illusion arises from a simple pattern: two tones generated by a computer, separated by a half-octave. (Musicians refer to this interval as a tritone.) Each tone is built out of components spaced an octave apart, which makes its perceived pitch height ambiguous. If one tone of a pair is sounded and then the second follows, certain listeners perceive an ascending sequence. Yet others, hearing that very same pair of tones, perceive it as descending instead.
For a gathering of musicians, all firmly convinced of their own judgments yet in total disagreement over whether the pair of tones rises or falls in pitch, this experience can be especially astonishing. The notion that the tritone was prohibited in music until modern times is simply a myth.
9. Mosquito Sound
This is a very high-pitched tone, listed at 18,000 Hz. Some young people can hear it, but hearing varies from person to person, and there is no fixed age cutoff.
A similar sound has been used as a ringtone that some adults are less likely to hear. High-frequency sounds have also been used to discourage groups of teenagers from gathering in public spaces. Hearing sensitivity at high frequencies often declines with age, but it does not switch off at a particular birthday. This is a demonstration of hearing range rather than an auditory illusion.
8. Welfare/Farewell Illusion
Unlike the Shepard tone, which is sometimes compared to M. C. Escher’s staircase illusion, this illusion uses a repeated spoken word. You may hear “Welfare” or “Farewell”, and what you hear can change as you listen.
Listen to the Welfare/Farewell illusion
7. Scale Change Illusion
This illusion was discovered by Diana Deutsch and is an example of our brains’ “grouping” similar notes together. Two major scales are played: one ascending and one descending. However, the notes alternate from ear to ear – for instance, the right ear hears the first note of one scale, and then the second note of the other.
There are several ways in which people perceive these sounds, but the most common is to group the high and low notes. Rather than hearing the two scales, people hear a descending and re-ascending melody in one ear, and an ascending and descending melody in the other. In other words, the brain reassigns some of the notes to a different ear to make a coherent melody. Right-handed people tend to hear the high melody in the right ear, and the low one in the left, while left-handers show a more diverse response.
6. Virtual Haircut
This is a demonstration of the stereo effect. Listening to it, you feel as though you are in a barber’s chair, with the barber moving around you, clipping away at your hair. As the barber “moves” to your right, the volume increases slightly in the right channel and decreases in the left.
Similarly, increases in the volume of sound from the clippers give the impression that he is bringing them closer and closer to each ear. The illusion demonstrates our ability to locate sounds in space; by comparing the inputs to the two ears, we can work out where a sound is coming from.
5. Phantom Melodies
Some pieces of music consist of high-speed arpeggios or other repeating patterns, which change only subtly. If they’re played fast enough, the brain picks up on the occasional notes that change and links them together to form a melody. The melody disappears if the piece is played slowly.
Play this recording of Christian Sinding’s Frühlingsrauschen (“Rustle of Spring”) at normal speed, then try it at a slower playback speed. At the higher speed, the changing notes linger in your perception long enough to be linked into a melody, but at the lower speeds, they’re too widely separated.
Fast: Watch at normal speed
Slow: Watch and set playback speed to 0.25×
4. Shaking Matchbox
In this illusion, a shaking matchbox is moved around your entire body. It’s so realistic that you feel an invisible/virtual matchbox moving around your body.
3. Quickening Beat
This recording is subtle. A beat sounds as if it keeps quickening, even though layers of rhythm cycle through the same range of tempos.
2. Falling Bells
This is a recording of a paradox where bells sound as if they are falling through space. As they fall, their pitch seems to be getting lower, but in fact, the pitch gets higher. If you loop this sample, you will see the pitch jump back down when the sample repeats.
This reveals that the start pitch is much lower than the finishing pitch. The illusion can be felt if the sample is looped in an audio player.
1. Shepard’s Ascending Tones
This recording demonstrates Shepard’s paradox, described by Roger Shepard. Jean-Claude Risset later developed a continuously rising version. The layered tones sound as if they are advancing up the scale, even though the overall pitch range repeats.
If you loop this sample seamlessly, then it should be impossible to tell where the sample begins and ends. It seems like the tone is ascending even if you loop the sample on your audio player.
Honorable Mention: The McGurk effect
Did you like our list of the top 37 audio illusions? Which one is your favorite? Let us know in the comments below!
I too enjoy audio illusions