Sound Test - 2

The pitch of the sound is proportional to the frequency of the sound. The greater the frequency, the higher the pitch.
The frequency of the sound is proportional to the square root of the tension. The greater the tension, the greater the frequency.
So, we can say that when a sitarist tries to adjust the tension and pluck the strings suitably, by doing so he is adjusting the frequency of the sitar strings with the frequency of other musical instruments.

The pinna is the only visible part of the ear with its special helical shape. It is the first part of the ear that reacts with sound. The function of the pinna is to act as a kind of funnel which assists in directing the sound further into the ear.

The middle ear is the part of the ear between the eardrum and the oval window. The middle ear transmits sound from the outer ear to the inner ear. The middle ear consists of three bones (i.e. the hammer (malleus), the anvil (incus) and the stirrup (stapes)), the oval window, the round window and the Eustachian tube.

The eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the air to the ossicles inside the middle ear and then to the oval window in the fluid-filled cochlea.

The function of the cochlea is to transform the vibrations of the cochlear liquids and associated structures into a neural signal. These signals are then passed to the auditory nerve and carried up to the brain.

At the end of the auditory canal, there is a thin membrane called eardrum or tympanic membrane. Eardrum is forced to vibrate due to pressure vibrations in air. A set of bones in the middle ear (hammer, anvil and stirrup) amplify these vibrations of the eardrum and forward these to the inner ear.

Eardrum is made to vibrate due to pressure variations in air. Bones in the middle ear amplify these vibrations of the eardrum and forward these to inner ear. Then, these vibrations get converted into electrical signals by cochlea. An electrical signal is sent to the brain through the auditory nerve and is interpreted as sound.

Here, time taken by an echo to return = 0.3 s
So, 2d = v × t
2d = 344 × 0.3
2d = 103.2
or, d = 51.6 m
∴ Distance of the reflecting surface from the source of sound is 51.6 m

Speed of sound depends upon the nature of the medium and the temperature of surroundings. As two sound waves travel in the same medium under same conditions, their speeds will be same. So, the ratio of their speeds is equal to 1 : 1.