Year 6 Science Quiz: Human Ear, Sound, and Light

The Human Ear and Hearing

• The human ear consists of three parts: the outer ear, middle ear, and inner ear.
• The pinna (or auricle) collects sound waves and directs them into the ear canal.
• Sound waves travel through the ear canal, hitting the eardrum, causing it to vibrate.
• The three tiny bones in the middle ear (ossicles) are the malleus, incus, and stapes.
• The cochlea is responsible for converting sound vibrations into electrical signals.
• The brain interprets these electrical signals as sound.
• It's essential to protect our ears from loud sounds to prevent damage and hearing loss.
• Examples of situations where loud noises can harm your ears include construction sites, concerts, and loud music through headphones.
• Earplugs are devices inserted into the ear canal to reduce noise levels, protecting the ears.
• Earplugs work by blocking or reducing the amount of sound that enters the ear.

Sound and Hearing Protection

• Earmuffs are devices that fit over the ears to protect them from loud noises.
• To determine if the noise level is too high, you can use a sound level meter or follow the rule of thumb: if you need to shout to be heard, the noise level may be too high.
• Foam earplugs are effective because they can reduce noise levels by 15-30 decibels.
• Consequences of not protecting your ears from loud noises include hearing loss, tinnitus, and ear pain.
• The 'Can you hear me?' activity demonstrates the importance of hearing protection.
• Wearing ear protection at construction sites is crucial to prevent hearing damage.
• Loud music through headphones can cause permanent hearing loss if played at high volumes for extended periods.
• The difference between earplugs and earmuffs is that earplugs are inserted into the ear canal, while earmuffs fit over the ears.
• If you're exposed to loud noises at work, you should take regular breaks to give your ears a chance to rest.
• The auditory nerve carries electrical signals from the cochlea to the brain, where they are interpreted as sound.

Light and Reflection

• When light hits a shiny surface, it bounces back, a process called reflection.
• A plane mirror is a flat, smooth mirror that produces a virtual image.
• Words like 'AMBULANCE' appear reversed on vehicles because of the way the letters are reflected in the mirror.
• Convex mirrors are curved outward, making them thicker in the middle than at the edges.
• Concave mirrors are curved inward, making them thinner in the middle than at the edges.
• Convex mirrors are commonly used in stores, parking garages, and cars to provide a wider view.
• Concave mirrors form images by reflecting light onto a focal point, creating a real image.
• A virtual image is an image that appears to be behind the mirror, but is not actually there.
• Convex mirrors provide a wider view because they are curved, allowing you to see more area.
• An example of a concave mirror in everyday use is a magnifying mirror.

Activities and Observations

• The purpose of using concave mirrors in telescopes is to magnify distant objects.
• Concave mirrors form real and virtual images by reflecting light onto a focal point.
• Convex mirrors are used in buildings to provide a wider view and to reduce blind spots.
• The activity involving two mirrors and a plastic toy demonstrates the concept of multiple images.
• Multiple images form when using two mirrors at an angle because light is reflected back and forth between the mirrors.
• When placing an object between two mirrors, you can observe multiple images and reflections.
• The reflective surfaces in the mirror activity create multiple images by reflecting light.
• You can use a concave mirror to get a magnified image by placing the object close to the mirror's focal point.
• The benefit of using convex mirrors in cars is that they provide a wider view, reducing blind spots.

How Our Senses Help Us Gather Information

Sound Production

• Sound is produced when an object vibrates.
• Examples of vibrating objects that produce sound: ruler, wooden stick, elastic bands, stretched wires or strings, and pipes.

Changing the Pitch of a Sound

• Pitch refers to how high or low a sound is.
• Pitch can be changed by making changes to the object creating the sound.
• Examples:
  • Tightening an elastic band increases the pitch.
  • Loosening an elastic band decreases the pitch.
  • Shortening a vibrating string increases the pitch.
  • Lengthening a vibrating string decreases the pitch.

Musical Instruments

• Musical instruments are designed to produce sounds through vibrations.
• Examples:
  • Guitar strings vibrate when plucked.
  • Trumpet produces sound when a column of air vibrates by buzzing lips while blowing air through a mouthpiece.
• Instruments have ways to change the pitch of the sound produced.
  • Guitar: pressing down on strings at different points changes the length of the vibrating string.
  • Trumpet: adjusting the opening between the lips or pressing valves while blowing into the mouthpiece changes the pitch.

Shoebox Guitar Activity

• Resources needed: shoebox, elastic bands, scissors/utility knife, pencil/spacers, and round bowl/circle template.
• Steps:
  1. Draw and cut out a circle on the shoebox top.
  2. Wrap elastic bands around the box, passing over the hole.
  3. Use pencils as spacers on either side of the shoebox.
  4. Pluck the elastic bands to produce sounds and change the pitch by tightening or loosening them.