Unit: 1 Sound and Hearing

Fill in the blanks:

1. Sound is a form of _________________ that produces the sensation of hearing.
2. Sound is produced due to _________________ of objects.
3. Sound cannot travel in _________________.
4. The unit of frequency is _________________.
5. The unit of intensity is _________________.
6. High frequency produces _________________ pitch sound.
7. A tuning fork produces _________________ sound.
8. Human hearing range is from _________________ Hz to _________________Hz.
9. _________________ helps us identify different sounds.
10. Children learn speech by _________________ and imitation.

Answers:

1. Energy
2. Vibrations
3. Vacuum
4. Hertz (Hz)
5. Decibel (dB)
6. High
7. Simple
8. 20 and 20,000
9. Timbre
10. Listening

Tick the correct answer:

1. Sound travels through:

a) Vacuum

b) Air

c) Nothing

2. Which of the following has high pitch?

a) Drum

b) Bell

c) Thunder

3. Loudness depends on:

a) Frequency

b) Force applied

c) Colour

4. Which is an unpleasant sound?

a) Music

b) Bird chirping

c) Traffic noise

5. A newborn responds to sound by:

a) Speaking

b) Startle response

c) Singing

Answers:

1. b) Air
2. b) Bell
3. b) Force applied
4. c) Traffic noise
5. b) Startle response

True or False

1. Sound can travel in vacuum.
2. Frequency determines pitch.
3. High intensity means soft sound.
4. Timbre helps identify sound quality.
5. Hearing is important for communication.

Answers:

1. False
2. True
3. False
4. True
5. True

Match the following

Column A	Column B
1. Frequency	a. Loudness
2. Intensity	b. Pitch
3. Timbre	c. Quality
4. Simple sound	d. Single frequency
5. Complex sound	e. Many frequencies

Answers:

1–b

2–a

3–c

4–d

5–e

Very short answer type questions:

1. What is sound?
2. What is vibration?
3. What is frequency?
4. What is intensity?
5. What is auditory behaviour?

Answers:

1. Sound is a form of energy that produces the sensation of hearing.
2. It is the back-and-forth movement of an object.
3. Number of vibrations per second.
4. Amount of energy used to produce sound.
5. It is how a child responds to sound at different ages.

Short answer type questions:

1. How is sound produced?
2. Why can sound not travel in vacuum?
3. Differentiate between high pitch and low pitch.
4. What are pleasant and unpleasant sounds?
5. What is the role of hearing in learning?

Answers:

1. Sound is produced when an object vibrates. These vibrations disturb air particles and create sound waves that reach our ears.
2. Sound needs a medium (air, liquid, solid) to travel. In vacuum, there are no particles to carry sound waves.
3. High pitch is produced by fast vibrations (high frequency), while low pitch is produced by slow vibrations (low frequency).
4. Pleasant sounds are soft and soothing (music), while unpleasant sounds are loud and disturbing (noise, traffic).
5. Hearing helps in speech development, understanding language, learning new words, and correcting pronunciation.

Long answer type questions:

1. Explain the properties of sound.
2. Explain the range of human hearing.
3. Describe the development of auditory behaviour in children.
4. Explain the functions of hearing.
5. Explain the role of hearing in learning and speech development.

Answers:

1. Sound has several important properties that help us understand and differentiate between different types of sounds. The two main properties of sound are frequency and intensity. Frequency refers to the number of vibrations produced in one second and determines the pitch of the sound. A high frequency produces a high-pitched (sharp) sound, while a low frequency produces a low-pitched (deep) sound. Intensity refers to the amount of energy or force used to produce sound and determines its loudness. A high intensity results in a loud sound, whereas a low intensity produces a soft sound. In addition to these, sound also has other properties. Duration refers to how long a sound lasts, such as the ringing of a bell. Timbre, also known as quality, helps us distinguish between different sounds even if they have the same pitch and loudness, such as the difference between the sound of a guitar and a piano.
2. The range of human hearing refers to the range of frequencies and intensities that a normal human ear can detect. Humans can typically hear sounds with frequencies between 20 Hz and 20,000 Hz. Sounds below 20 Hz are called infrasonic and those above 20,000 Hz are ultrasonic, which cannot be heard by humans. In terms of intensity, the human ear can detect sounds from 0 dB, which is the softest sound, up to 120 dB, which is the level at which sound becomes painful or uncomfortable. The speech range lies between 200 Hz and 8000 Hz, which is important for understanding spoken language. Sounds above 120 dB can cause discomfort and may even damage hearing.
3. Auditory behaviour refers to how a child responds to sound at different stages of development. This development occurs gradually as the child grows. A newborn baby typically shows a startle response to loud sounds, such as sudden body movement or waking from sleep. By around 4 months of age, the child begins to turn their head towards the source of sound. By 1 year, the child responds to their name and familiar sounds. By the age of 2 years, the child can locate sounds coming from different directions, including soft sounds. Overall, auditory development progresses from simple reflex actions, like startle responses, to more purposeful behaviours such as recognizing, locating, and responding to sounds.
4. Hearing is one of the five important senses and plays a vital role in daily life. One of its primary functions is detecting danger, such as hearing a vehicle horn and moving away to stay safe. Hearing also provides enjoyment and relaxation, for example, by listening to music or watching movies. It is essential for communication, as it helps us understand speech and respond appropriately in conversations. Hearing also plays a key role in learning to speak, as children learn speech by listening to others and imitating them. Additionally, hearing helps us gain knowledge about the world, as we learn through listening to instructions, lectures, and conversations. Thus, hearing is important for safety, communication, enjoyment, and learning.
5. Hearing plays a crucial role in both learning and speech development. Children learn to speak by listening to others and imitating their speech sounds. They begin to associate sounds with objects and actions, which helps in developing language skills. Hearing also allows individuals to learn continuously throughout life by listening to new words, ideas, and information. It helps in understanding language and improving vocabulary. Another important role of hearing is that it enables individuals to monitor their own speech, allowing them to check and correct their pronunciation. Therefore, hearing is essential not only for the development of speech and language but also for maintaining and improving these skills over time.