- Joined
- Dec 27, 2001
- Location
- In the lab
FAQ: "How loud is my fan?" and other noise questions
What I'm doing here is basically trying to put together a FAQ on noise levels and decibels.
So, “How loud is my fan?”
Well, that all depends on the decibel level.
The decibel scale is based on powers of 10, or in other words, it’s a logarithmic scale. For the few of you who understand how the pH scale works, it’s similar.
The lowest level of sound audible to a human being is defined as 0 decibels. Every time the sound wave gets 10 times more intense, you add 10 decibels. Here is a good link explaining it.
“How does this compare to my stock heatsink?”
Here is a list of heatsinks made by coolermaster. These are generally what AMD and system builders use. Note that they range between 33 and 42 decibels.
Intel does not note any specifications, but note that here, a sound meter with a minimum of 50db does not detect the stock heatsink at 8”. This means that it is at MOST 36db.
“How is fan noise measured?”
Most companies state that they measure the noise level at 1 meter, or about 39 inches, from the fan.
“What if I use two quiet fans?”
Note that if you double the intensity of the sound wave, the decibels increase by about 3. This is NOT a good indicator of how loud it seems. To the ear, an increase of 10 decibels is twice as loud.
“Will I be able to sleep in the same room as my computer?”
Maybe. At about 45 decibels, a person cannot sleep. Fortunately, sound intensity decreases with distance. The decrease does not depend on the initial noise level, and it only depends on the relative distance. That means that something will be X deceibels quieter if you double the distance, no matter whether you start from 1 foot away or you start from 10 meters away. Here’s a quick calculator to tell you how much quieter it will be. For those of you who use a 57 decibel tornado, that means you’ll have to be 13 feet from your computer if you even hope to sleep.
“So, wait a minute… if the decibel drop doesn’t depend on the initial noise level, then couldn’t I get negative decibels?”
Sure. And it would be a good way to measure the sound. Keep in mind, though, that you can’t hear anything under 0 decibels.
“How loud can it be before it damages my hearing?”
Huh? Did you just say something?
Well, a sustained noise of 85 decibels can damage hearing. You’d have to have 645 tornado fans running at the same time to reach that! Or you could just hold your ear 2 inches from the fan. Of course, the latter is more likely to damage your hearing by cutting off your ear.
Keep in mind, though, that if you can’t hear that delta or tornado fan over your speakers/headphones, you may be damaging your hearing. You won’t feel pain until about 130 decibels.
What I'm doing here is basically trying to put together a FAQ on noise levels and decibels.
So, “How loud is my fan?”
Well, that all depends on the decibel level.
The decibel scale is based on powers of 10, or in other words, it’s a logarithmic scale. For the few of you who understand how the pH scale works, it’s similar.
The lowest level of sound audible to a human being is defined as 0 decibels. Every time the sound wave gets 10 times more intense, you add 10 decibels. Here is a good link explaining it.
“How does this compare to my stock heatsink?”
Here is a list of heatsinks made by coolermaster. These are generally what AMD and system builders use. Note that they range between 33 and 42 decibels.
Intel does not note any specifications, but note that here, a sound meter with a minimum of 50db does not detect the stock heatsink at 8”. This means that it is at MOST 36db.
“How is fan noise measured?”
Most companies state that they measure the noise level at 1 meter, or about 39 inches, from the fan.
“What if I use two quiet fans?”
Note that if you double the intensity of the sound wave, the decibels increase by about 3. This is NOT a good indicator of how loud it seems. To the ear, an increase of 10 decibels is twice as loud.
“Will I be able to sleep in the same room as my computer?”
Maybe. At about 45 decibels, a person cannot sleep. Fortunately, sound intensity decreases with distance. The decrease does not depend on the initial noise level, and it only depends on the relative distance. That means that something will be X deceibels quieter if you double the distance, no matter whether you start from 1 foot away or you start from 10 meters away. Here’s a quick calculator to tell you how much quieter it will be. For those of you who use a 57 decibel tornado, that means you’ll have to be 13 feet from your computer if you even hope to sleep.
“So, wait a minute… if the decibel drop doesn’t depend on the initial noise level, then couldn’t I get negative decibels?”
Sure. And it would be a good way to measure the sound. Keep in mind, though, that you can’t hear anything under 0 decibels.
“How loud can it be before it damages my hearing?”
Huh? Did you just say something?
Well, a sustained noise of 85 decibels can damage hearing. You’d have to have 645 tornado fans running at the same time to reach that! Or you could just hold your ear 2 inches from the fan. Of course, the latter is more likely to damage your hearing by cutting off your ear.
Keep in mind, though, that if you can’t hear that delta or tornado fan over your speakers/headphones, you may be damaging your hearing. You won’t feel pain until about 130 decibels.
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