It’s diffcult to hear someone talking when they’re in a place where wind is blowing fast. It might feel like the wind is blowing the words away. Is that what’s really happening?
Read the five answers below to get a good understanding of the science behind this phenomenon.
The reason this happens is due to the refraction of the sound waves. They refract as the wind speed increases with altitude, so even in strong winds, the wind speed at your feet is practically 0. This effect in a headwind causes the sound to refract upward and be lost faster and a tailwind the sound refracts downwards. If you google sound refraction in wind there are some good images which show the effect clearly.
As an interesting side fact: professional golfers always assume that whatever speed the wind is traveling by them will be accelerated the higher their ball travels, and adjust accordingly.
So if they feel there’s a somewhat consistent light wind heading Southeast, they’ll aim accordingly to the ball being blown a bit more to the Southeast if they’re counting on making a lofty shot.
Since wind is invisible, not doing so is understandably a rookie mistake.
Firstly, the wind doesn’t need to cancel the sound, only dampen it to the point of it not being clear.
Secondly, sound and wind are not two constant forces in exact opposition to each other. They are at varying angles, of varying strengths and in varying phase to each other.
The reality is that the wind noise plays a major part in not hearing things, mostly because it’s loud, but also because it’s a fairly wide spread of different frequencies, but the wind speed, direction and wave pay a role too, one which could be enough on its own to obscure the sound enough to make it difficult to hear
Wind can also change the direction of a sound, so those down wind can hear well because the sound is being channeled towards them.
The only way for your words to be completely “blown away” would be for the wind to be moving at the speed of sound (about 767 mph). Since you’d be dead if you were exposed to winds of that speed, it’s just the wind noise drowning the sound out.
Sound is basically mechanical vibrations in the medium (in this case, air) so any movement in air is going to impact how well someone will receive the sound coming from you. As well as other noise in the medium will affect the transmission of sound too. If you are in really strong wind, depending on the angle of the wind between two of you, it can seriously change how well they can hear you.
Another thing to keep in mind is that your voice doesn’t need to be completely “blown away” for it to be indiscernible. If it is at the same or lower amplitudes as compared to other sounds in the environment, the reciever will have a hard time understanding you as well.
The wind is moving at the speed of sound it can’t be “blown away” however a strong wind can make a sound dissipate more than it would in still air, making the noise seem artificially farther away. Think of rowing a boat up stream, you could travel the same distance as still water but more energy would be lost to get there.
The shape of the current is more important than the speed and direction. A perfectly linear wave will propagate the sound as a package inside the greater compression wave. This is essentially what happens in a full frequency speaker like a headphone speaker, where the entire spectrum is created by a unidirectional driver.
When the current in the wind is chaotic, it causes those compression waves to lose cohesion and phase cancel. The more chaotic, the more damping occurs.