Question

Fill in the following blanks with suitable words : 

(a) Sounds are produced by ………….. objects. 

(b) The human voice box is called ………….. 

(c) Sound cannot travel in ……………….. 

(d) A set of three tiny…………in the middle part of ear passes on sound vibrations from the eardrum to the liquid in the cochlea. 

(e) The unit of frequency is …………..

(f) The time taken by an object to complete one oscillation is called………

(g) The shrillness of a sound is determined by the ………..of vibration. 

(h) Unpleasant sound is called………………. 

(i) Sound which is pleasing to the ear is called…………….sound. 

(j) A person having partial hearing loss can hear properly by wearing a device called hearing ……………on the ear.

Answer 1

(a) Sounds are produced by vibrating objects. 

(b) The human voice box is called larynx 

(c) Sound cannot travel in vacuum 

(d) A set of three tiny bones in the middle part of ear passes on sound vibrations from the eardrum to the liquid in cochlea. 

(e) The unit of frequency is Hertz (Hz) 

(f) The time taken by an object to complete one oscillation is called time-period 

(g) The shrillness of a sound is determined by the frequency of vibration. 

(h) Unpleasant sound is called noise. 

(i) Sound which is pleasing to the ear is called musical sound. 

(j) A person having partial hearing loss can hear properly by wearing a device called hearing machine on the ear.