Science [7 marks Questions]

1. The outer and visible part of the human ear is called pinata (curved in shape).
2. It is specially designed to gather sound from the environment, which then reaches the eardrum (tympanic membrane) through the ear canal.
3. When the sound wave strikes the drum, the vesicles move inward and outward to create the vibrations.
4. These vibrations are then picked up by special types of cells in the inner ear. From the inner ear, the vibrations are sent to the brain in the form of signals.
5. The brain perceives these signals as sounds.
Human Ear

1. Strict guidelines should be set for the use of loudspeakers on social, religious, and political occasions.
2. All automobiles should have effective silencers.
3. People should be encouraged to refrain from excessive honking while driving.
4. Industrial machines and home appliances should be properly maintained.
5. All communication systems must be operated in low volumes.
6. Residential areas should be free from heavy vehicles.
7. A green corridor belt should be set up around the industries as per the regulations of the pollution control board.
8. People working in noisy factories should wear earplugs.
9. People should be encouraged to plant trees and to use absorbing materials like curtains and cushions in their homes.

• Loudness:

1. It is defined as the characteristic of a sound that enables us to distinguish a weak or feeble sound from a loud sound.
2. The loudness of a sound depends on its amplitude.
3. Higher the amplitude louder will be the sound and vice-versa.
4. When a drum is softly beaten, a weak sound is produced. However, when it is beaten strongly, a loud sound is produced.
5. The unit of the loudness of sound is the decibel (dB).

• Pitch:

1. The pitch is the characteristic of sound that enables us to distinguish between a flat sound and a shrill sound.
2. The higher the frequency of sound, the higher will be the pitch. High pitch adds shrillness to a sound.
3. The sound produced by a whistle, a bell, a flute, and a violin is high pitch sounds.

• Quality or Timbre:

1. The quality or timbre is the characteristic of sound that enables us to distinguish between two sounds that have the same pitch and amplitude.
2. For example in an orchestra, the sounds produced by some musical instruments may have the same pitch and loudness.