What is the noun for whisper?

There isn't a single perfect noun for "whisper" because it depends on the context. Here are some options:

General:

* Whispering: A general term for the act of whispering.

* Whisper: Can be used as a noun to refer to a specific instance of whispering.

* Murmur: A softer, more indistinct whisper.

More specific:

* Hush: A very quiet whisper.

* Rustle: A whispering sound, often associated with leaves or clothing.

* Mutter: A quiet, often mumbled whisper.

* Sussurro: (Italian) A soft, gentle whisper.

The best choice depends on the specific situation and the meaning you want to convey.