Formula for sound dissipation in air?

In summary, the dissipation of sound waves in air is governed by two factors: the inverse square law, which states that the intensity of sound decreases with distance, and absorption, which is dependent on frequency and humidity. Both effects occur simultaneously and contribute to the attenuation of sound over distance.
  • #1
Ralphonsicus
47
0
Is there an equation that deals with the dissipation of sound waves in air? As in, how much they die out with distance, because we know they must, otherwise you could hear me talking now!
 
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  • #2
The intensity is inversely proportional to the radius squared.

That is, if a certain source has a power P and it emits pressure waves spherically, the intensity I you'll hear is

[tex]I = \frac{P}{4\pi r^2}[/tex]
 
  • #3
There is also some absorption, which depends on frequency (proportional to frequency squared) and humidity. This produces an attenuation which is proportional to distance (as opposed to inverse square law). Both effects occur at the same time.

See this link.
 

What is the formula for sound dissipation in air?

The formula for sound dissipation in air is given by D = 20 log (d) + 20 log (f) + 8, where D is the sound dissipation in decibels, d is the distance from the sound source in meters, and f is the frequency of the sound in Hertz.

How is sound dissipation affected by distance from the source?

As per the formula D = 20 log (d) + 20 log (f) + 8, distance from the sound source has a logarithmic effect on sound dissipation. This means that as the distance increases, the sound dissipation also increases at a slower rate.

What role does frequency play in sound dissipation?

The frequency of sound plays a significant role in sound dissipation. As seen in the formula D = 20 log (d) + 20 log (f) + 8, a higher frequency means a higher sound dissipation, leading to a decrease in the loudness of the sound.

Are there any other factors that affect sound dissipation in air?

Aside from distance and frequency, there are other factors that can also affect sound dissipation in air. These include temperature, humidity, and wind speed. Higher temperatures and humidity levels can increase sound dissipation, while wind speed can either increase or decrease it depending on the direction of the wind.

How is the formula for sound dissipation in air used in real-world applications?

The formula for sound dissipation in air is commonly used by acoustical engineers to design and predict the sound levels in various environments. It is also used in noise control measures to reduce the impact of sound on human health and the environment. Additionally, it is used in the development of noise regulations and guidelines for different industries.

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