When dry leaves blow around on a windy day, it creates rustling noise. By physics, sound is created when the disturbance waves travels at the speed of sound in the medium. Also, the speed of the wave is dependant on the pressure change in the medium. Collaborating all these, the question is, does the leaves contact with the ground have so much pressure change in the surrounding?
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga.
Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus.
Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
Hoot! You just asked your first question! Hang tight while I find people to answer it for you. You can thank people who give you good answers by clicking the 'Good Answer' button on the right!
A friend of mine told me that the threshold of hearing is 20 micro-pascal (rms, 20 * 10^-6 Pa). Compare that with atmospheric pressure - 100kPa (10^5 Pa). The slightest sound we can hear has a pressure nearly only 1/5000,000,000 times the atmospheric pressure. The leaves don't have to create all that much pressure change for us to hear.
Threshold? isnt threshold of hearing in Hertz? 20hz-20khz? how is it dependent to pressure? and the explanation from there holds reasonable.
Not the answer you are looking for? Search for more explanations.
That is the frequency threshold. There is also an additional loudness threshold
ok. if you can provide me some credible source to refer to your claim, it would do me great help. Otherwise, thanks a lot for the reply.
I actually heard this from my friend - who happens to be a rocket engineer. I also saw the same figure on wiki: http://en.wikipedia.org/wiki/Sound_pressure
I know that the above two don't really count as credible. But then, this site[ http://www.sengpielaudio.com/TableOfSoundPressureLevels.htm ] also refer to the same figure. Hope that helps
As a matter of fact, this site has enormous amount of info into audio and audio processing. I am just leaving the link here so that someone may find it useful:
The key part is under the title 'Sound Pressure Levels'.