Page 91 - Viva ICSE Science 5 : E-book

TIME TO REVISE

Fill in the blanks.

1. The second hand of a clock produces a soft ___________ sound.
2. A pressure cooker makes a ___________ sound.
3. Plants and trees make ___________ sound when their leaves move due to ___________.
4. ___________ sounds include talking, singing, whispering, etc.

Pleasant and Unpleasant Sounds

Some sounds make us feel happy and relaxed. Such sounds are pleasant sounds. We
enjoy a pleasant sound. Usually, we fi nd low-pitched sounds or harmonious sounds
pleasing. Some examples of pleasant sounds are as follows.

• Melodious singing
• Music played in tune on various musical instruments like harmonium, sitar, fl ute or

guitar
• Laughter of small children

• Chirping of birds

• Leaves rustling during gentle breeze
• Sounds of waves on a beach

man playing guitar girl laughing bird chirping
Some pleasant sounds

Sounds which are not good to hear and disturb us are unpleasant sounds. Unpleasant
sounds are also called noise. Such sounds make us feel irritated and uncomfortable.

We feel like closing our ears. Unpleasant sounds are usually high-pitched, piercing or
tuneless. Some examples of unpleasant sounds are as follows.
• Very loud music

• Tuneless music

• Sound produced by loudspeakers

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