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Sound Intensity Calculator

Use this Sound intensity calculator to convert intensity to decibels by entering the values input box.

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Formula

Sound intensity level formula:
IL = 10 log10 (I/I0)

Sound Intensity Equation (Formula):
I = I0 * 10 IL/10

Reference Intensity:
I0 = I/10 IL/10

Where,
IL = Sound Intensity Level,
I = Sound Intensity,
I0 = Reference Intensity.

What are sound and sound waves?

Anything we hear from our ears is called sound. Sound is transferred in the form of waves. These waves are known as sound waves. 

Sound waves need a medium to propagate, that’s why they are called longitudinal waves. Another name for sound waves is acoustic waves.

Sound intensity

The power or force with which a sound wave carries energy while propagating through a specified area is called sound intensity. 

Sound intensity level or acoustic intensity level is a logarithmic measure of the sound intensity in comparison to the reference level.

Different voices have different sound intensities. For example; the sound produced by a bird is less intensive than one produced by a car. 

Unit

It is represented by I. Its unit is watt per meter square. Which is derived from the formula 

I=p/A

Where P stands for power and A for the area. The relationship between sound intensity and its amplitude is;

I=(∆Pmax)2/2pv

Sound intensity at a distance:

When someone standing close to us says something we hear it clearly. But if the same person with the same frequency is talking to you from a distance, you will have trouble understanding. 

It proves that sound intensity changes with distance. It is because sound waves are interrupted more when they have to travel more. 

How is sound intensity calculated manually?

Although the above-mentioned formula is of sound intensity, there is another more accurate way to find the sound intensity. If the sound intensity is calculated in decibels, it is of more practical use.

Decibel:

It is a unit that measures the sound intensity along a logarithmic scale. It is much more common and accurate. It is used in different fields of physics like electronics, communication, e.t.c. 

db =log10I/I0

Sound below 75 decibels is commonly considered safe and if you are exposed to above 75 decibels for a long period, it can damage your hearing. 

The following table has examples of sound with their decibel intensity.

Decibels 

Examples 

0

Silence 

10

Breathing

20

Rustle of leaves

30

Whispering 

40

Refrigerator, computer hum

 50

Rain

60

Conversation

70

Shower, flush, car

80

A truck, loud radio

90

Lawnmower, hairdryer

100

Helicopter, subway train

110

Trombone, rock band

120

Airplane on taking off, police siren

130

Threshold of pain

140

Fireworks

150

Gunshot 

160

Fighter jet

170

Rocket launch

Instrument used:

The most common sound intensity finder is the SPL meter. Its calibration is often decibels.

How to use Sound Intensity Calculator? 

The sound intensity calculator is used to find the intensity of sound. It is also known as the decibels calculator as it can also convert DB to intensity. Sound

Intensity is defined as the sound power Pac per unit area A. 

  • Choose what you want to calculate.
  • Let’s assume you want to calculate reference intensity.
  • Put the other two values in their labeled boxes.
  • Click calculate.

Also, don’t forget to visit our sound pressure level calculator.

Example: 

For given values of I = 45 and I0 = 1

SIL = 10 log10 45/1

SIL = 16.5321 decibel

For a specified direction and point in space, the average rate at which sound energy is transmitted through a unit area perpendicular to the specified direction is called sound intensity.

Difference between sound intensity and sound intensity level:

This difference can be defined as sound intensity is the rate of sound moving through a region while sound intensity level is a ratio. It is a ratio between any sound to the faintest sound a human can hear.

References: 

  1. Sound Intensity - an overview | Topics. Sciencedirect.com.
  2. what is Sound Intensity. Engineeringtoolbox.com
  3. Decibel. Britannica.com.