Sci Eye Hearing the Sound

00:19:15
https://www.youtube.com/watch?v=yhgM50ofKcQ

Summary

TLDRThe video elucidates the concept of sound, comparing sound waves to waves on a slinky. It describes how sound is created by the vibrations of objects like drums, which compress air and create waves. The ear's structure is detailed, explaining how sound waves are captured, transformed into vibrations, and then converted into electrical signals sent to the brain. The speed of sound is discussed in different mediums, and demonstrations show sound detection using explosions. The video also covers frequencies, showing how human hearing varies and the effects of loud sounds on hearing health.

Takeaways

  • πŸ”Š Sound is created by vibrating objects.
  • 🎢 Sound waves travel through air and other materials.
  • πŸ‘‚ The ear has several components that convert sound waves into signals for the brain.
  • ⚑ Sound travels faster through solids than through air.
  • 🎼 High frequencies correlate to high-pitched sounds; low frequencies to low-pitched sounds.
  • πŸ§ͺ Experiments show how sound is detected differently based on the medium.
  • 🚨 Loud sounds can lead to permanent hearing damage.
  • πŸ›‘οΈ Protection for ears is crucial for those exposed to loud music.
  • πŸ“ˆ Human hearing has limits, notably above 16,000 Hz and below 20 Hz.
  • πŸ‘¨β€πŸŽ€ DJs and others need to be cautious about their ear health.

Timeline

  • 00:00:00 - 00:05:00

    The video begins by explaining the nature of sound and how it travels as a sound wave, using the analogy of a slinky spring to visualize compression and energy transfer. It describes the process of sound generation when a drum is struck and how sound waves propagate through air and solids, emphasizing the movement of air particles and the role of the ear in detecting sound, which includes the ear drum, ossicles, and cochlea.

  • 00:05:00 - 00:10:00

    The video progresses to an experiment involving an explosion, where participants listen for the sound waves. The results show that light travels faster than sound, and sound travels faster through solid materials than air. It also discusses sound frequency, explaining how different pitches are perceived in the ear based on where they are detected in the cochlea, highlighting the similarities between microphones and human ears in converting sound waves into electrical signals.

  • 00:10:00 - 00:19:15

    In the final segment, the focus shifts to human hearing and the effects of loud noise exposure. The results of a hearing experiment reveal that Angela, who works in a noisy environment, has diminished hearing at high frequencies due to potential damage from loud sounds. The video concludes with a discussion on protective measures for hearing, stressing the importance of awareness about sound exposure and potential long-term effects.

Mind Map

Video Q&A

  • What is sound?

    Sound is a wave that travels through air (or other mediums) created by vibrating objects.

  • How does sound travel?

    Sound travels through vibrations in the air or other materials, carrying energy while the particles return to their original positions.

  • What parts of the ear detect sound?

    The fleshy part of the ear, the pinna, funnels sound waves to the eardrum, which vibrates and transfers the signal to the inner ear.

  • How do different pitches of sound work?

    High pitch sounds have a high frequency, resulting in more compressions every second, while low pitch sounds have a lower frequency.

  • What can damage hearing?

    Loud sounds, especially high frequency sounds, can damage the cells in the cochlea, affecting our ability to hear certain frequencies.

  • How fast does sound travel through air and ground?

    Sound travels at about 350 m/s in air and much faster, at around 5,000 m/s, through solid materials like ground.

  • What are the effects of loud music?

    Frequent exposure to loud music can lead to hearing difficulties, particularly at high frequencies.

View more video summaries

Get instant access to free YouTube video summaries powered by AI!
Subtitles
en
Auto Scroll:
  • 00:00:01
    [Music]
  • 00:00:14
    [Music]
  • 00:00:30
    there are lots of different ways to make
  • 00:00:32
    a
  • 00:00:34
    [Music]
  • 00:00:55
    sound but what is sound for example how
  • 00:00:58
    do you hear the sound of a
  • 00:01:01
    [Music]
  • 00:01:09
    drum a sound wave is like the wave you
  • 00:01:12
    can make on a slinky
  • 00:01:18
    spring you put energy into it by pushing
  • 00:01:21
    one
  • 00:01:23
    end this compresses the
  • 00:01:26
    spring the compression travels along
  • 00:01:29
    carrying the energy with
  • 00:01:32
    it each coil is pushed forward and then
  • 00:01:35
    Springs back to its starting
  • 00:01:43
    point what carries the wave when you
  • 00:01:45
    hear a
  • 00:01:48
    sound the air in the room is made up of
  • 00:01:50
    tiny particles although in real life the
  • 00:01:53
    far too small to
  • 00:01:56
    see when a drum skin is struck it bends
  • 00:01:59
    outwards and compresses the air in front
  • 00:02:02
    of
  • 00:02:03
    it it's the compression that moves
  • 00:02:05
    through the air leaving the air
  • 00:02:07
    particles back where they
  • 00:02:15
    started in real life the drum vibrates
  • 00:02:18
    dozens of times every second so a
  • 00:02:20
    soundwave is made up of lots of
  • 00:02:23
    compressions but how do you hear
  • 00:02:28
    them you might think ears are just the
  • 00:02:30
    fleshy things on the side of your head
  • 00:02:33
    but there's more to them than
  • 00:02:35
    that the fleshy part is called the
  • 00:02:38
    Pinner its job is to F the sound waves
  • 00:02:41
    into the
  • 00:02:43
    ear the next thing the sound waves hit
  • 00:02:46
    is the ear drum which vibrates just like
  • 00:02:48
    an ordinary
  • 00:02:50
    drum then the vibration continues
  • 00:02:53
    through three tiny Bones called the
  • 00:02:57
    oses the ccka is in the inner ear it's
  • 00:03:00
    coiled up like a snail
  • 00:03:02
    shell the oses pass on the wave to a
  • 00:03:06
    liquid inside the
  • 00:03:08
    cockier the movement of the liquid is
  • 00:03:10
    picked up by cells shaped like tiny
  • 00:03:15
    hairs they send the signal to the brain
  • 00:03:17
    along a
  • 00:03:20
    nerve the ear converts sound waves into
  • 00:03:24
    electrical signals which the brain can
  • 00:03:28
    recognize
  • 00:03:32
    if you don't believe that air vibrates
  • 00:03:35
    take a look at
  • 00:03:45
    [Music]
  • 00:03:48
    this soundwaves can travel through solid
  • 00:03:50
    things like wood as
  • 00:03:55
    well the particles in a solid are packed
  • 00:03:58
    together far more tightly than air
  • 00:04:02
    particles what difference do you think
  • 00:04:04
    this makes to the sounds you
  • 00:04:11
    hear listening with a stethoscope can
  • 00:04:16
    hurt does sound travel faster in the
  • 00:04:18
    ground or through the
  • 00:04:21
    air and is the speed of sound ever as
  • 00:04:24
    fast as the speed of
  • 00:04:25
    [Music]
  • 00:04:28
    light to find out you need to make a
  • 00:04:31
    sound that can travel a long distance
  • 00:04:33
    five tons of plastic explosives should
  • 00:04:35
    do the
  • 00:04:46
    [Music]
  • 00:04:48
    trick how would he detect sound waves in
  • 00:04:51
    the
  • 00:04:56
    [Music]
  • 00:04:58
    ground
  • 00:05:01
    [Music]
  • 00:05:15
    Samantha's going to watch for the
  • 00:05:17
    explosion but she's wearing headphones
  • 00:05:19
    so she can't hear
  • 00:05:27
    it Fong is going to listen for it so
  • 00:05:31
    he's wearing a
  • 00:05:32
    blindfold and Elizabeth's going to
  • 00:05:35
    detect sound waves in the
  • 00:05:37
    [Music]
  • 00:05:45
    ground ready
  • 00:05:48
    [Music]
  • 00:05:52
    ready so who's going to be the first
  • 00:05:55
    second and third to detect the
  • 00:05:58
    explosion
  • 00:06:00
    [Music]
  • 00:06:42
    they were waiting to see the
  • 00:06:45
    light hear the
  • 00:06:49
    sound or feel the
  • 00:06:51
    [Music]
  • 00:06:54
    sound Samantha was first because the
  • 00:06:56
    light got to them before the sound
  • 00:07:03
    Elizabeth was next when she felt the
  • 00:07:05
    sound coming through the
  • 00:07:09
    ground and Fung was
  • 00:07:12
    last when he heard the sound of the
  • 00:07:15
    explosion coming through the
  • 00:07:18
    air the speed of sound in the air is 350
  • 00:07:22
    m/
  • 00:07:24
    second at 5,000 m/s sound travels much
  • 00:07:28
    faster through the ground
  • 00:07:33
    but light is much faster than any sound
  • 00:07:35
    at 300 million m/
  • 00:07:42
    [Applause]
  • 00:07:50
    second sounds can be low pitched or high
  • 00:07:58
    pitched
  • 00:08:03
    [Music]
  • 00:08:10
    a high pitch sound is a high frequency
  • 00:08:12
    sound that means there are more
  • 00:08:14
    compressions every
  • 00:08:18
    second but how do you hear the
  • 00:08:20
    difference between sounds of different
  • 00:08:24
    pitch a microphone is like an
  • 00:08:28
    ear
  • 00:08:29
    inside there's a diaphragm connected to
  • 00:08:32
    Electric
  • 00:08:33
    wires like the eardrum it vibrates when
  • 00:08:36
    sound waves strike it one two this
  • 00:08:40
    creates an electric current in the wires
  • 00:08:43
    which you can look at on a computer
  • 00:08:44
    screen 7
  • 00:08:47
    8 1 2 3 4 5 6 7
  • 00:08:58
    8
  • 00:09:00
    a trumpet has a higher pitch so it makes
  • 00:09:03
    a different picture on the computer
  • 00:09:06
    [Music]
  • 00:09:11
    screen ears work in a similar
  • 00:09:16
    way when a low frequency sound enters
  • 00:09:19
    the ear it's detected at the very center
  • 00:09:22
    of the
  • 00:09:23
    ccka and the brain recognizes a low
  • 00:09:26
    frequency
  • 00:09:28
    sound
  • 00:09:30
    [Music]
  • 00:09:33
    when a high frequency sound comes in it
  • 00:09:35
    gets detected in a different place
  • 00:09:37
    nearer the entrance of the
  • 00:09:42
    cocka this makes a different electrical
  • 00:09:45
    signal and the brain recognizes a high
  • 00:09:48
    frequency
  • 00:09:56
    sound you can make a musical instrument
  • 00:09:58
    out of of just about
  • 00:10:00
    anything we need
  • 00:10:03
    it if you can make something vibrate at
  • 00:10:06
    the right frequency you can get a
  • 00:10:08
    musical
  • 00:10:13
    note the bhone works by changing the
  • 00:10:16
    length of the tubes a shorter tube gives
  • 00:10:18
    a higher
  • 00:10:22
    [Music]
  • 00:10:28
    pitch
  • 00:10:29
    [Music]
  • 00:10:37
    go how are they changing the pitch of
  • 00:10:39
    the other
  • 00:10:41
    instruments
  • 00:10:51
    [Music]
  • 00:10:58
    it's
  • 00:11:03
    the frequency can depend on the size or
  • 00:11:05
    length of whatever's
  • 00:11:11
    [Music]
  • 00:11:16
    vibrating what else can the frequency
  • 00:11:18
    depend
  • 00:11:22
    on a piece of wire can make a musical
  • 00:11:25
    note but how are they making it loud
  • 00:11:27
    enough to hear
  • 00:11:29
    [Music]
  • 00:11:57
    think
  • 00:11:59
    uh well yeah
  • 00:12:01
    [Music]
  • 00:12:27
    nearly
  • 00:12:32
    [Music]
  • 00:12:57
    the
  • 00:13:00
    [Music]
  • 00:13:19
    how good is human hearing at different
  • 00:13:27
    frequencies this is a signal generator
  • 00:13:29
    it can make a whole range of
  • 00:13:32
    frequencies and they can change the
  • 00:13:34
    volume as
  • 00:13:41
    well the speaker is vibrating 50 times
  • 00:13:45
    every second so the frequency of this
  • 00:13:47
    sound is 50
  • 00:13:49
    [Music]
  • 00:13:54
    htz Angela and Sam put their hands up as
  • 00:13:57
    soon as they can hear the sound and
  • 00:13:59
    Kieran takes a not of the volume for
  • 00:14:01
    each of
  • 00:14:04
    them Caroline increases the frequency
  • 00:14:06
    and they start
  • 00:14:27
    again
  • 00:14:43
    here are the results the frequency goes
  • 00:14:45
    along the bottom the volume required to
  • 00:14:48
    hear the sound goes up the
  • 00:14:51
    side Angela's hearing is about the same
  • 00:14:54
    at most frequencies the volume had to go
  • 00:14:57
    up to about two before she could hear
  • 00:15:00
    it like most people her hearing isn't
  • 00:15:03
    quite so good at high frequencies so the
  • 00:15:05
    volume had to go up a little bit
  • 00:15:11
    higher human hearing is limited above
  • 00:15:14
    about 16,000 Herz and below 20 htz
  • 00:15:17
    Angela can't hear anything no matter how
  • 00:15:19
    loud the
  • 00:15:22
    sound Sam's results were about the same
  • 00:15:24
    as
  • 00:15:27
    Angela's Angela has a job where there's
  • 00:15:29
    a lot of loud noise so how will it
  • 00:15:31
    affect her
  • 00:15:33
    hearing Sam's putting on headphones he's
  • 00:15:36
    the control in this
  • 00:15:40
    experiment Angela is otherwise known as
  • 00:15:42
    DJ
  • 00:15:44
    [Music]
  • 00:15:49
    angel I don't usually wear a protection
  • 00:15:51
    when I'm DJing because um I like to hear
  • 00:15:54
    the music um fully I like to hear what
  • 00:15:57
    the crowd hears
  • 00:16:00
    um usually when I finished the gig my
  • 00:16:02
    hearring is a little bit muffled and it
  • 00:16:03
    takes a while for it to just back to
  • 00:16:05
    normal
  • 00:16:07
    again I suppose I really should wear ear
  • 00:16:09
    protection when I'm working to protect
  • 00:16:12
    my ears but it would make life that
  • 00:16:13
    little bit more
  • 00:16:15
    [Music]
  • 00:16:19
    [Applause]
  • 00:16:21
    [Music]
  • 00:16:27
    difficult
  • 00:16:32
    after the gig they do the same
  • 00:16:34
    experiment
  • 00:16:37
    again what do you think's going to
  • 00:16:57
    happen
  • 00:17:01
    [Music]
  • 00:17:04
    Sam's hearing is about the same as
  • 00:17:05
    before but the volume has to be turned
  • 00:17:08
    up before Angela can hear
  • 00:17:10
    [Music]
  • 00:17:27
    it
  • 00:17:31
    at high frequencies she has real
  • 00:17:33
    difficulty hearing the
  • 00:17:45
    sound here are Angela's results from
  • 00:17:51
    before afterwards the volume had to be
  • 00:17:53
    turned up much higher especially at high
  • 00:17:57
    frequencies
  • 00:17:59
    what do you think's happened inside her
  • 00:18:04
    ears remember high frequency sounds are
  • 00:18:07
    detected near the entrance of the
  • 00:18:10
    cockier so those cells are more likely
  • 00:18:12
    to be damaged by loud sounds and to stop
  • 00:18:15
    [Music]
  • 00:18:19
    working a very loud high frequency sound
  • 00:18:22
    can damage the cells for
  • 00:18:27
    good
  • 00:18:29
    loud music shouldn't damage your hearing
  • 00:18:32
    permanently but listening to it every
  • 00:18:34
    day could cause Angela
  • 00:18:38
    problems what precautions should she
  • 00:18:40
    take while she's
  • 00:18:42
    [Music]
  • 00:18:57
    working
Tags
  • Sound
  • Waves
  • Hearing
  • Eardrum
  • Frequency
  • Pitch
  • Vibration
  • Sound Travel
  • Hearing Loss
  • Sound Experiment