Sound Test - 38

The eardrum, also called the tympanic membrane, is a thin, cone-shaped membrane that separates the external ear from the middle ear. The vibrations produced in the eardrum allow you to hear the sound. Damage to the eardrum makes us deaf.

Sound is produced when an object vibrates, creating a pressure wave. This wave causes particles in the surrounding medium to vibrate. The particles transmit this energy to nearby particles , which is perceived by human ears as sound if the frequency of vibration lies in the audible range.

The audible range of hearing for average human beings is in the frequency range of $$20\ Hz – 20\ kHz.$$

Infrasound is the sound where the rate of vibration is too low for us to hear

Ultrasound is the sound  where the rate of vibration is too high for us to hear

Ultrasound is used to see what is happening in a nuclear reactor.Ultrasounds and infra sounds are not audible to man.Ultrasound have frequency more than 20kHz. Infrasound have frequency below 20Hz.An earthquake produces infrasound before the mainshock wave begins.

Since Z can be heard by a person so Z is in audible range and it is audible sound.

If we blow a flute, the air column vibrates and produces sound. The flute contains small air columns when the air is bowed through the mouthpiece the air columns start vibrating which produces sound.

Musical sound:

1. It is a periodic disturbance that repeats itself at regular intervals.

2. There is no sudden change in amplitude or loudness.

3. It is sufficiently rapid so that it can be ensured as a sense of continuity.

Noise:

1. It is a non-periodic disturbance.

2. There are, very often, irregular sudden changes in amplitude or loudness, or both.

3. There is no sense of continuity.

Cotton act as a sound absorber so when we put it inside the ear, damps the vibration entering the ear. and when the damped sound reaches the eardrum, its vibration becomes lower than the original. So, we find it difficult to hear.

Steel having the higher density of all the materials mentioned. so it will transmit sound at the highest speed.

• We do not hear sound of explosions from Sun as there is no medium in between the earth and the sun. 

Noise pollution can be reduced by using silencers in vehicles, industrial machines, and home appliances reducing use of vehicle horns, running TV, radio and music systems at low volumes. Planting of trees along roads and buildings also help to reduce noise pollution.Noise mufflers are also used to avoid noises.