What brings the sound of a ringing telephone bell to our ears?

How does a sound making object differ from one that is silent?

Name the part which vibrates to produce sound in the following:

(a) Drums

(b) Sitar

(c) Flute

What is the length of vocal cords in a man?

Out of a man and a woman:

(a) who has shorter vocal cords?

(b) who produces sound of higher pitch?