🎯 What you will learn

1. Identify and group everyday sounds from nature, people, animals and machines.
2. Explain how pleasant and unpleasant sounds and music affect our mood.
3. Classify musical instruments as blowing, beating or vibrating strings.
4. Describe how vibrations make sound and carry it to our ears and brain.
5. Explain why warning sounds matter, how loud noise harms us and suggest ways to reduce noise pollution.

🗺️ Road map

Think: Which sounds in the story came from living things? Which came from machines or objects?

Topic 1: Everyday Sounds and Foley Sounds

🌍 Sounds All Around Us

We hear sounds at home, at school, on the road and in nature. The thing that makes a sound is called the sound source. Sounds come from many sources:

• Nature: rain, thunder, wind, flowing water and the rustling of leaves.
• Living things: a person talking, a dog barking, a crow cawing, a cat meowing.
• Machines and objects: a fan, a mixer grinder, a pressure cooker, a train, a school bell.

We can group sounds in many ways. For example: loud and soft, high and low, pleasant and unpleasant, natural and man-made, or sounds made by electrical things and sounds made without electricity. Some sounds, like a ticking clock or a drum beat, repeat in a pattern. This pattern is called rhythm.

🐺 Animals Use Sound

Animals use sounds to talk to each other. Birds sing to call their friends and warn of danger. A wolf howls to tell the pack where it is, and the other wolves howl back, even from far away. Whales and elephants also use sounds that travel a long distance to stay in touch.

🎬 Movie Sounds Made by Foley

In films, small sounds like footsteps often get lost, or the action is so loud that they cannot be heard. A Foley artist fixes this. Foley artists work in a quiet studio and use everyday objects to make sounds that match what is on the screen:

• Breaking bones: snapping celery or carrot sticks.
• Rustling clothes: rubbing pieces of cloth together.
• Footsteps: walking in shoes on a tray of sand, leaves or gravel.

Without Foley sounds, a car chase with no screeching tyres or a fight with no punches would feel empty and boring.

Topic 2: Pleasant Sounds, Unpleasant Sounds and Music

😊 Pleasant and Unpleasant Sounds

Pleasant sounds are gentle and soothing, and they make us feel good. They often have a nice rhythm or melody, like birds singing, soft music or leaves rustling in the wind.

Unpleasant sounds are harsh, loud or irritating. They can make us feel uncomfortable or stressed, like screeching brakes, a loud horn or nails scratching a chalkboard.

The same sound can feel pleasant to one person and unpleasant to another. A loud dhol at a festival may make you want to dance, but it can disturb a sleeping baby. Even an unpleasant sound can be useful. The sharp ring of an alarm clock wakes us up on time.

🎶 How Music Changes Our Mood

Music can make us feel happy, sad or want to dance. When we listen to music we like, our brain releases a chemical called dopamine. It gives us a feeling of pleasure, just like when we eat something tasty. We can enjoy music even if we do not understand the words, because the beat, the tune and the rhythm speak to us. Film makers use fast music for action scenes and slow music for sad scenes to change how the audience feels.

🥣 Can an Unpleasant Sound Become Pleasant?

Tap empty steel glasses gently with a spoon. The sound is harsh. Now add some water to the glasses in different amounts and tap again. The sounds change and now you can make a tune! This is the idea behind the Jal Tarang, a traditional Indian instrument made of bowls filled with water and struck gently with sticks.

🎺 Let’s Create Music

Musical instruments make sound in three main ways:

Each instrument has its own special sound. You can change the sound by changing something, like tightening a string or changing how much water is in a bowl.

Topic 3: How Sound Travels

〰️ Sound Is Made by Vibrations

Sound is a form of energy that is produced when objects vibrate. When we talk, clap, pluck a rubber band or strike a steel ruler, the object moves back and forth very fast. This movement is called a vibration, and it makes sound.

🌊 How Does the Sound Reach Us?

Think of dropping a pebble into still water. The ripples spread out in all directions. Sound waves spread in the same way from the source through the air. Air is full of tiny, invisible particles. When something vibrates, it makes the nearby air particles move back and forth. They bump into their neighbours and pass the energy along, like a row of falling dominoes. In this way the energy of the sound travels from the source to our ears.

🔬 Experiment: From Music to Motion

You need: a small container, a balloon or plastic wrap, rubber bands, a little salt or pepper and a Bluetooth speaker.

1. Stretch the balloon tightly over the mouth of the container and hold it with a rubber band.
2. Sprinkle some salt or pepper on top.
3. Play music very close to the container. Start with a deep drum beat. Then try a high-pitched song.
4. Keep the volume the same first. Then increase it slowly.

Safety: Keep the volume moderate. Keep the salt, pepper and the speaker away from water and loose wires, and do the activity with an adult.

What you will see: The grains jump. They jump more when the volume is higher. If you touch the side of the container gently, you can feel a tiny movement. This is because the sound makes the balloon vibrate. We cannot see sound, but we can see what it does.

Topic 4: Warning Sounds, Loud Noise and Noise Pollution

🚨 Sounds of Safety

Warning sounds are made to be loud and clear so that people can react quickly in an emergency. Examples are an ambulance siren, a fire alarm, a smoke detector and the loud beep before an announcement at a railway station. A school bell is also a signal. It tells us when a period or a break begins. A siren may sound loud and unpleasant, but it is helpful because it warns people of an emergency. When we hear a siren, we move aside for the ambulance. When we hear a fire alarm, we leave the building calmly. Hospitals and libraries use softer sounds or flashing lights so they do not disturb people.

📏 Measuring Sound: Decibels

Sound is measured in decibels (dB). The higher the number, the louder the sound.

📢 What Is Noise?

Any unpleasant or harsh sound is called noise. Loud noise can harm our ears and our health. Hearing very loud sounds for a long time can damage the ears and lead to hearing loss. It can also cause stress, headaches, poor sleep and trouble concentrating. Constant noise from traffic or construction can even lead to high blood pressure and heart problems. Animals suffer too, because their hearing is often more sensitive than ours.

🏙️ Noise Pollution

Noise pollution happens when loud and harsh sounds fill our surroundings, especially in busy cities. Heavy traffic, construction machines, loudspeakers and firecrackers are common sources. A 2022 report by the United Nations Environment Programme (UNEP) found very high noise levels in several South Asian cities. Your textbook gives these figures:

Your textbook also says that the World Health Organization (WHO) suggests keeping noise at 55 dB in residential areas and 70 dB in traffic zones.

🔇 How to Reduce Noise Pollution

1. Use quieter equipment: choose quiet machines and repair old ones.
2. Soundproofing: use thick curtains or special foam on walls and windows.
3. Control noise at the source: make rules for construction sites, factories and traffic.
4. Raise awareness: teach people about the harm of noise.
5. Promote green spaces: plants and trees act as natural sound barriers.
6. Follow the rules: support and follow local noise control rules.

Each card has a picture and a two-line note. The second line is the key idea.

Picture Card 1: Sounds of a Morning

We hear many different sounds at home, from living things and from machines.
Key idea: Sounds come from people, animals, machines and nature.

Picture Card 2: The Foley Artist

A Foley artist makes film sounds with everyday objects like carrots, shoes and cloth.
Key idea: Foley sounds make films feel real.

Picture Card 3: Music Lifts the Mood

Music can make us feel happy, sad or want to dance.
Key idea: Music makes our brain release dopamine, which gives us pleasure.

Picture Card 4: The Jal Tarang

Each bowl with a different amount of water gives a different sound.
Key idea: Changing something in an instrument changes its sound.

Picture Card 5: Three Ways to Make Music

Instruments make sound by blowing, beating or vibrating strings.
Key idea: Every instrument has its own special sound.

Picture Card 6: From Music to Motion

Sound makes the stretched balloon vibrate and the grains jump.
Key idea: Where there is sound, there is vibration.

Picture Card 7: The Ambulance Siren

A warning sound is loud and sharp so that people notice it at once.
Key idea: Warning sounds help people act quickly in an emergency.

Picture Card 8: A Noisy City and a Quiet Park

Loud traffic is noise pollution. Trees and parks help to cut down noise.
Key idea: We can reduce noise with quiet machines, soundproofing, trees and rules.

The same mind map in words

Outline

1. Sources of Sound
   • Nature: rain, wind, birds
   • Living things: people, animals
   • Machines: fan, mixer, train
   • We can group sounds in many ways
2. Foley Sounds
   • Sound effects for films
   • Made with everyday objects
   • Celery or carrot = breaking bones
   • Rubbing cloth = rustling clothes
3. Pleasant and Unpleasant
   • Pleasant: gentle, soothing, with a rhythm
   • Unpleasant: harsh, loud, irritating
   • It can depend on the person
   • Music releases dopamine
4. Making Music
   • Blowing: flute, shehnai, nadaswaram
   • Beating: tabla, drums, mridangam
   • Vibrating strings: guitar, veena, violin
   • Jal Tarang: bowls with water
5. How Sound Travels
   • Vibration ➜ Medium (air) ➜ Ear ➜ Brain
   • Air particles pass the energy on
   • Eardrum vibrates, nerves carry signals
   • No sound in a vacuum
6. Warning Sounds
   • Siren, fire alarm, smoke detector
   • Loud and sharp on purpose
   • Help people act quickly
   • Hospitals use softer signals
7. Noise and Noise Pollution
   • Measured in decibels (dB)
   • Above 85 dB can damage hearing
   • Stress, headaches, poor sleep, heart problems
   • Reduce: quiet machines, soundproofing, trees, rules

Tap a card to flip it and see the answer. Try to say the answer first!

Part 1: Ten Short Answer Questions

Write each answer in 30 to 50 words. Try first, then tap to check.

Part 2: Five Long Answer Questions

Write each answer in 80 to 120 words: Introduction, Main points, Example and Conclusion.

Read each story. Then answer the five questions. Tap to see the answers.