First noticed this with Firestorm 7.1.12 (77610), there is a relatively quiet, murmuring wind noise looping constantly as long as the avatar is hovering but not moving. Not as loud as the wind noise when flying, so it is a different sound which is not supposed to be playing at all while stationary. This sound is also attached to the camera and not the avatar, so when zooming or moving the camera around the sound keeps playing, coming from the camera position. Upon stopping flying, the sound stops instantly, it seems to be consistent with the avatar hovering in one spot.

According to others this has already been present in Second Life Viewer 7.1.11. When I first tested it with Second Life Viewer 7.1.12 I couldn't hear this noise even though master and ambient volume settings were at maximum. Since others could hear it though I checked again and now I could hear the noise in this viewer as well, even though it wasn't as loud as in Firestorm.

The expected behavior of the avatar flight wind noise is to only play when moving up, down, forward, back, left or right, when simply hovering no noise should occur.

Steps to verify:

1: Stand still (no flying) - no wind noise

2: Fly up - after a brief wind noise that is supposed to be there while flying up, a quiet murmuring wind noise will loop constantly

3: Fly in any or all directions for a while - normal wind noise will play while moving

4: Stop moving - the quiet murmuring noise will keep looping again while hovering

5: Stop flying - the noise will stop immediately