posted by rfvv .
1. It is noisy outside.
2. It is too noisy and we can hardly hear each other.
3. It is too noisy for the man to sleep.
4. There must be a fight going on outside. It is way too noisy.
5. Anything doing? Why is it so noisy?
6. It is too ugly and too noisy.
7. It was noisy with the sound of many voices.
Are they all grammatical? Does 'it' refer to ambiguous environment? Is 'it' all 'an impersonal pronoun in each sentence?
All are fine. And yes, "it" is an impersonal pronoun here, more of an introductory word, just as "there" can be.