The Absorption of Sound vs. Relative Humidity.

I was told that the mist produced by mist maker will adversely effect the echolocation of swiftlet.
To my suspicion, I search google and found the below article of which I still not quite understand.
So anyone in here can lighten me up will be highly appreciated.


Effects of Humidity on Sound

Contrary to what most people believe, there
is more sound attenuation in dry air than in damp air.
The effect is a complex one, and it is shown in
Figure 1-11. Note that the effect is significant only
at frequencies above 2 kHz. This means that high
frequencies will be attenuated more with distance
than low frequencies will be, and that the attenuation
will be greatest when the relative humidity is 20
percent or less.



Credit to Sound System Design Reference Manual by JBL

Today,Dec 2nd, I was kindly advised by my friend who is a physicist that the above article explained that
lower Relative humidity has more effect to high frequency sound than higher humidity.
But he also remarked that mist and relative humidity cannot be considered as same thing.
As mist is still a fine droplet of water,but for relative humidity, water is evaporated as gaseous stage and is almost homogeneous to air.

I guess a good physicist will be a good BH owner as sound , ventilation , temperature , humidity are mainly physic.