here in a question asked by a student the expert is saying that sound is uncountable noun but in the activity of this chapter it is said that sound is countable noun how it is possible.plz send me the correct answer.

The word sound can be both countable and uncountable. However, in both cases, the meaning changes. If we say 'a sound', it will refer to one sound. Example: I heard a sound. However, if we say, The sound of piano is soothing. In this case, the word sound is an uncountable noun.

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