whispering

a. & n. from Whisper. v. t.

Whispering gallery, or Whispering dome, one of such a form that sounds produced in certain parts of it are concentrated by reflection from the walls to another part, so that whispers or feeble sounds are audible at a much greater distance than under ordinary circumstances.

Certain passages or galleries are referred to as ‘whispering’ on account of the facility and distinctness with which a whisper or low sound is transmitted through its extent. Examples are the passage above the choir and behind the east window of Gloucester Cathedral, and the circular internal gallery of the dome of St Paul's Cathedral, London.

The noun has 2 meanings:

Meaning #1: the light noise like the noise of silk clothing or leaves blowing in the wind
  Synonyms: rustle, rustling, whisper

Meaning #2: speaking softly without vibration of the vocal cords
  Synonyms: whisper, susurration

The adjective whispering has one meaning:

Meaning #1: making a low continuous indistinct sound
  Synonyms: murmuring, susurrant