Can You Trust Your Ears? (Audio Illusions)

Summary

This video script explores auditory illusions, challenging viewers to trust their ears. It introduces the McGurk effect, where visuals alter perceived speech sounds. It also demonstrates how sound can change perceived visuals, as in the circle flash illusion. The Tritone Paradox, influenced by geography and language, causes differing perceptions of ascending or descending tones. Lastly, the Shepard Tone Illusion creates an endless rising pitch, intriguing viewers about the profound impact of music on the mind.

Takeaways

• 👂 The McGurk effect demonstrates how visual cues can alter auditory perception.
• 🎵 Auditory illusions can change the way we interpret sounds, even when the audio remains constant.
• 👀 Visual stimuli can influence what we hear, as shown by the circle flashing illusion.
• 🎶 The Tritone Paradox is an auditory illusion where the brain prefers to focus on either a higher or lower frequency in a tone.
• 🌐 Geographic and linguistic factors from infancy can influence how we perceive auditory illusions.
• 🔁 The Shepard Tone Illusion creates a sense of a never-ending rise in pitch due to the way multiple sine waves are layered.
• 🎵 Music can have a profound and varied effect on our minds, which is further explored in the AsapTHOUGHT episode.
• 🤔 Trusting our ears can be deceptive as auditory illusions show.
• 📢 Engage with the content by asking questions in the comments or on social media.
• 🔔 Stay updated on episode ideas and behind-the-scenes content by following the creators on Instagram and Twitter.
• 📺 Subscribe for more weekly science videos to keep learning about fascinating phenomena.

Q & A

What is the McGurk effect mentioned in the script?

The McGurk effect is a perceptual phenomenon where the auditory perception of a speech sound is influenced by the visual information from a speaker's mouth movements. It demonstrates how our vision can alter what we believe we're hearing.

How does the visual information in the videos affect the auditory perception?

In the script, it's described that the same audio is perceived differently when paired with different visuals, such as seeing the word 'bar' or 'far'. This shows that our vision can influence our auditory perception.

What is the illusion where sound can alter our perceived vision?

The illusion where sound can alter our perceived vision is demonstrated by the circle flashing experiment. When accompanied by two beeps, people often perceive it as flashing twice, whereas without sound, it only flashes once.

What is the Tritone Paradox?

The Tritone Paradox is an auditory illusion where two tones are played, and listeners may perceive them as either ascending or descending. The paradox arises because the tones contain both higher and lower frequencies, and our brains tend to focus on one over the other.

How do geography and language from infancy influence the Tritone Paradox?

According to Diana Deutsch, the creator of the Tritone Paradox, factors such as one's geographical location and language exposure from infancy can influence the preference for perceiving the tones as ascending or descending.

What is the Shepard Tone Illusion?

The Shepard Tone Illusion is an auditory illusion where a series of tones seem to continuously rise in pitch. This is achieved by playing multiple sine waves that rise in pitch while one quickly drops an octave, creating the illusion of an endless ascent.

Why does the Shepard Tone Illusion create the perception of an endless rise in pitch?

The Shepard Tone Illusion creates the perception of an endless rise in pitch because our brain does not notice when one of the sine waves drops an octave while the others continue to rise, thus it sounds like the pitch is continuously increasing.

How can these auditory illusions explain the effect of music on our minds?

These auditory illusions can help explain the profound and varying effects of music on our minds by demonstrating how our perception can be influenced by auditory and visual cues, as well as cultural and linguistic factors.

What is the purpose of the experiment with two tones where listeners determine if they are ascending or descending?

The purpose of the experiment with two tones is to demonstrate the variability in auditory perception among individuals, highlighting the subjective nature of hearing and the role of personal biases in interpreting auditory information.

What does the script suggest about trusting our ears?

The script suggests that our ears can be deceived by auditory illusions, which challenges the notion that we can always trust our auditory perception. It encourages skepticism and curiosity about the reliability of our senses.

How can viewers engage with the content of the script?

Viewers can engage with the content by watching the AsapTHOUGHT episode mentioned in the script, asking questions in the comments or on social media platforms, and following the creators on Instagram and Twitter for behind-the-scenes insights.

Outlines

00:00

👂 The McGurk Effect and Auditory Illusions

This paragraph introduces the concept of auditory illusions, starting with the McGurk effect. It explains how visual cues can alter what we believe we're hearing, using the example of hearing 'bar' or 'far' depending on the video watched. It also discusses how sound can affect our perception of visual stimuli, as demonstrated by a circle that appears to flash twice when accompanied by the appropriate sound. The paragraph further explores the Tritone Paradox, where listeners may perceive different musical intervals due to the tones containing both higher and lower frequencies. The creator, Diana Deutsch, found that factors such as geography and language influence these perceptions. Lastly, it mentions the Shepard Tone Illusion, where a tune seems to climb indefinitely due to the brain not registering a drop in pitch, despite the clip being the same.

Keywords

💡Illusions

Illusions refer to deceptive appearances or impressions that lead the mind to interpret sensory input incorrectly. In the context of the video, illusions are sensory tricks that play with our perception, such as visual and auditory illusions that make us hear or see things differently from reality. The script mentions illusions of the ear, which are auditory illusions, and illusions of the eye, which are visual illusions.

💡McGurk Effect

The McGurk Effect is a perceptual phenomenon that demonstrates how our vision can influence what we hear. It is named after the researchers Harry McGurk and John MacDonald who first described it. The video uses this effect to show that when viewers look at a video with different visuals while hearing the same audio, they perceive different speech sounds. This illustrates how our brain integrates information from multiple senses.

💡Auditory Illusion

Auditory illusions are experiences where sounds are perceived differently from how they actually are. The video script provides examples of auditory illusions, such as the one where the sound seems to change based on the video being watched, even though the audio remains the same. This concept is central to the video's theme of exploring how our senses can be tricked.

💡Tritone Paradox

The Tritone Paradox is an auditory illusion where two tones are played that contain both a higher and lower frequency, but our brains tend to focus on one or the other. This illusion is mentioned in the script to show how individual perception can vary, and how factors like geography and language can influence which frequency we perceive as dominant.

💡Shepard Tone Illusion

The Shepard Tone Illusion is a sound illusion where a sequence of tones seems to be continuously rising or falling in pitch, but it is actually a loop. The video script uses this illusion to demonstrate how our brains can be tricked into perceiving a continuous increase or decrease in pitch, even though the sound is repeating.

💡Perception

Perception is the process by which the brain interprets sensory information from the environment. The video explores how perception can be influenced by illusions, both auditory and visual. It shows how our senses can be deceived, leading to different interpretations of the same stimuli.

💡Sensory Input

Sensory input refers to the signals received by the sensory organs that are then processed by the brain. The video discusses how sensory input can be interpreted incorrectly due to illusions, leading to experiences that do not match objective reality.

💡Diana Deutsch

Diana Deutsch is a psychologist and musician known for her work on auditory illusions. The video script mentions her as the creator of the Tritone Paradox illusion, highlighting her contribution to the understanding of how our brains process sound.

💡Geography

Geography, in the context of the video, refers to the influence of one's geographical location on perception. The script suggests that where a person is from can affect how they perceive certain auditory illusions, like the Tritone Paradox.

💡Language

Language is mentioned in the video as a factor that can influence auditory perception. The script implies that the language a person is exposed to from infancy can shape how they interpret auditory illusions, such as which frequency they focus on in the Tritone Paradox.

💡Sine Waves

Sine waves are a type of waveform that oscillates smoothly between positive and negative values. In the context of the Shepard Tone Illusion, sine waves are layered on top of each other to create the illusion of a tone that seems to be continuously rising in pitch.

Highlights

Illusions of the ear can trick our auditory perception.

The McGurk effect demonstrates how visuals can alter auditory perception.

Audio can influence what we believe we're hearing without changing.

Visuals can change the sound we hear, as shown by the 'bar' and 'far' illusion.

Sound can alter perceived visual stimuli, as seen with the circle flash illusion.

Auditory illusions can be experienced differently by different people.

The Tritone Paradox creates auditory illusions based on frequency perception.

Preferences in auditory illusions can be influenced by geography and language.

The Shepard Tone Illusion creates a seemingly endless rising tune.

Multiple sine waves are used in the Shepard Tone to create an illusion of continuous rise.

The brain doesn't register the drop in pitch in the Shepard Tone Illusion.

Music can have a profound and varying effect on our minds.

The new AsapTHOUGHT episode explores whether music can save your life.

Engage with the content by asking questions in the comments or on social media.

Stay updated on episode ideas and behind-the-scenes content through social media.

Subscribe for more weekly science videos.

Transcripts

Many of us have become quick to catch illusions that trick our eyes - but how often do you

consider illusions of the ear? Are you really able to trust your ears and the things they hear?

For example, listen to Greg speaking...

What do you hear? If you heard 'bar, bar, bar' you'd be right. But, how about now?

Chances are you heard 'far, far, far' this time, with an 'F'. Except, you didn't - in fact, the audio didn't even

change between the two videos. Strange as it seems, what you hear depends on which video

you are looking at. Go ahead - take turns watching each video and see how the sound

morphs. This is a perfect example of something called the McGurk effect, which shows how

our visuals can alter what we believe we're hearing.

Now I want you to count how many times you see a circle flash on screen. Lets do that

once more time. Did you see it flash twice? Many people do. Yet, without the sound, it

becomes clear that the circle is only flashing once. In this case, the sound has altered

your perceived vision.

This next one works best with other people around. I'll play two tones, and you tell

me if they are ascending or descending. In other words, are the notes played from low

to high, or high to low? Listen to this.

Which was it? How about this one?

Write down what you heard for each number, and let us know in the comments. Chances are, if you

compare with enough people, you'll all have different answers. Surprising? Try some more.

And this one.

How is it possible that you're hearing something different from

others? It's an auditory illusion called the Tritone Paradox. It's created in such a way

that the tones contains both a higher and lower frequency in them, but our brains have

a preference of which to listen to. Diana Deutsch, the creator of this illusion, found

that your geography and language from infancy all play a role in deciding this preference.

Finally, listen to this audio clip of a gradually climbing tune.

And yet, if I play the exact

same clip back to you, it will sound like it's only continuing to climb higher and higher.

I swear this is the exact same clip I just played - you can rewind that section of this

video over and over and check yourself. Try it! Each time you start it over, the tune

is seemingly climbing even higher. It's called the Shepard Tone Illusion, of which there

are many variations. In it, multiple sine waves are played on top of one another raising

in pitch, while one quickly drops down an octave as the others continue rising. But

our brain doesn't notice this drop, and so the clips sound like they are rising...forever!

These illusions may help to explain how something like music can have such a profound yet varying

effect on our minds, which we discuss in our new AsapTHOUGHT episode here, along with the question

of whether or not Music Can Save Your Life. There's a link in the description to watch it!

So...do you still trust your ears?

Got a burning question you want answered? Ask it in the comments or on Facebook or Twitter.

And if you want the inside scoop on upcoming episode ideas and behind the scenes,

check out our personal Instagram and Twitter handles.

And subscribe for more weekly science videos!