In one of the activites you treated 'sound' as contable noun. But according to your experts 'sound' is a uncountable noun. Plese clarify.
This concept might confuse you a bit but with passage of time and more practice in English you would surely get a strong hold in this.
Sound is a word which can be treated as a countable as well as an uncountable noun.
Here are examples for your better understanding:
- I could not sleep because of the various sounds coming from the jungle.
- The sounds of the different instruments kept ringing in my ears till late.
- Sound travels slower than light.
- Decible is a unit to measure sound.
- Sound can travel long distances.