In which medium, air or water, an echo is heard much sooner? Why?

Fill in the following blanks with suitable words:

(a) An echo is simply a ………. Sound.

(b) Pitch od sound depends on ………

(c) Loudness of sound depends on ……….

(d) Quality of sound depends on ……….

(e) Echoes are caused by the …………of sound.

On which day, a hot day or a cold day, an echo is heard sooner? (Give reason for your answer.

What is reverberation? What will happen if the reverberation time in a big hall is too long?

How can reverberations in a big hall or auditotium be reduced?