There are three small bones in the middle ear.

(a) Name the three bones

(b) Which of these bones is in touch with oval window ?

(c) Which of these bones is in touch with the ear drum ?

(d) Which bone is in touch with the other two bones?

Three different vibrating objects produce three types of sounds X, Y and Z. The sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X can be heard by a bat whereas the sound Y can be heard by a rhinoceros. What type of sounds are X, Y and Z?

Your parents are going to buy a house. They have been offered one house on the roadside and another house three lanes away from the roadside. Which house would you suggest your parents should buy ? Explain your answer.

The sound from an insect is produced when it vibrates its wings at an average rate of 500 vibrations per second:

(a) What is the time-period of the vibrations ?

(b) What is the frequency of the vibrations in hertz ?

(c) Can we hear this sound? Why or why not?

Explain why, if we strike a steel tumbler with a metal spoon lightly, we hear a feeble sound but if we hit the tumbler hard, a loud sound is heard.