There appears not to have been much discusion on sound phenomena associated with tornadic events. Originating from my reasoning (In: 13 Dec 2008 Stanthorpe NE cell ) that this was possibly a landspout event is based solely on the fact of the intensity, type and localised direction of the noise associated with this event. I have listed a few questions below.
The noise of the 13th Dec event I previously described as a "few Chinook's in the back of the storm", relates to the fact the noise was resonating, which I had interpreted as resulting from probable rotational funnel interaction with trees on the land surface.
So I like to would pose a couple of questions.
1.Is the above interpretation a possible correct assumption?
2. Would a funnel which is not in contact with the ground be almost silent or again is this variable? (in the sound range audible to the human ear).
3. How much does the intensity and resonation of noise, vary depending on the landscape surface i.e. flat, bare / amount and type of vegetation?
4. Can the broader surrounding inflow still create a similar intense noise including resonation or would it lack resonation and be similar to straight line winds of equal speeds?
It seems in most cases the first indication of a tornado approaching is what is general described as the sound "like a freight train approaching" etc although it appears they can produce a variety of sounds.
Has there been any Australian based studies into noise of vortices and tornadic events?
Even though tornadic events are a lot rarer in australia is there much / any Australian evidence, or experience into the sounds made by tornadoes
There appears to be are few publications of US research into this subject.
e.g. NOAA Infrasonics Program
http://www.esrl.noaa.gov/psd/programs/infrasound/ (into sound below the range of human hearing)
Paul
Sounds assocaited with Tornadoes and related atmospheric features