Page 89 - Viva ICSE Science 5 : E-book

8 Sound and Noise

Diff erent sounds are produced every moment KEY CONCEPTS

from various things around us. Our ears help
us to hear these sounds. Diff erent things, both • Sounds of some common objects
• Sounds made by living beings
living and non-living, produce diff erent types of
• Pleasant and unpleasant sounds
sounds. Some sounds are loud, while some are • Warning sounds
soft. Some sounds are pleasant, while some may • Noise pollution
be unpleasant.

Sounds of Some Common Objects

We hear a variety of sounds throughout the day. From the time we wake up, till the
time we go to sleep, we keep hearing diff erent sounds. We get so used to hearing these

sounds that we can even recognise the objects which make these sounds.

• As the second hand of a clock moves, it produces a soft ‘tick-
tock’ sound. We can hear it all the time in a silent room. We tick-tock!

also set an alarm on the clock to wake us up. Alarm is louder
than the softer ‘tick-tock’.

• Sound produced by a doorbell is loud. It attracts our
attention indicating that someone is at the door.

• Sound made by a whistle also attracts our attention, whether
it is made by a person or an object. In our kitchen, a tea kettle
or a pressure cooker makes a whistling sound when they

release steam. While the sound made by tea kettle may be hiss!
a low whistle, pressure cooker usually makes loud whistle.

• Utensils in the kitchen make various sounds depending

upon the material they are made up of. A steel plate falling
will have diff erent sound than a glass plate falling and
breaking.

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