# Decibel Question (adding I think)

• Hit an Apex
In summary, to increase the number of machines without exceeding the 90 db limit set by federal regulations, 1 additional machine must produce an 80 dB noise level.
Hit an Apex
Question at hand, A noisy machine in a factory produces a decibel rating of 80 dB. How many identical machines could you add to the factory without exceeding the 90 dB limit set by federal regulations?

I just did a bunch of other problems regarding h/z and m/s and they were all right , so I don't understand why this program is on webassign. Anyway, 1 machine is producing 80db and I need to figure out how many more machines they can add without going over 90db.

I'd love to know where to start...

What is the connection between Bells and Watts...?

Daniel.

Hit an Apex said:
Question at hand, A noisy machine in a factory produces a decibel rating of 80 dB. How many identical machines could you add to the factory without exceeding the 90 dB limit set by federal regulations?

I just did a bunch of other problems regarding h/z and m/s and they were all right , so I don't understand why this program is on webassign. Anyway, 1 machine is producing 80db and I need to figure out how many more machines they can add without going over 90db.

I'd love to know where to start...
Decibels are measured using common logarithms (except, with a "deci-" prefix, you're actually measuring tenths of a Bel).

The common log of 2 is approximately .301, or, very approximately, .3. That's not a very appealing number, so, by using decibels (tenths of a Bel), we get 3 decibels.

The common log of 10 is 1.0, the common log of 100 is 2.0, the common log of 1000 is 3.0, etc. In decibels, the above would be 10, 20, 30, etc.

Isn't it from A.G.Bell?As Watt from J.Watt?

Daniel.

dextercioby said:
Isn't it from A.G.Bell?As Watt from J.Watt?

Daniel.
Yes, but it's stilled spelled with just one 'l'.

Why, I'm not quite sure. I know a few coorporations donated some vowels to a Eastern European relief effort, due to the scarcity of vowels in the names of Eastern European people. Maybe Bell Telephone Labs made a similar effort to seed the Finnish-Czechoslavakian http://www-linguistics.stanford.edu/Linguistics/Archives/Sesquipedalian/1992-93/msg00006.html .

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An increase of 10 dB means that the power ratio in the definition of the dB has to increase by 10. Can you calculate what the power ratio with one machine running is? Do you know what the reference power is?

Or you could simply do the math so its applicable to any level increase.

n * 10^8 = 10^9

This would be in bels (divide by 10 to convert decibels to bels)

Or to show what BobG looks like as a simple bit of math:

2 * 10^8 = 10^8.3

Or you could just do an antilog on the difference too. Like for the number of machiens to result in a 6db increase we have 10^0.6 = 4 times the initial number of machines.

## 1. What is a decibel and how is it measured?

A decibel (dB) is a unit used to measure the intensity of sound. It is a logarithmic unit, meaning that it is based on a logarithm scale. The formula for calculating decibels is 10 log (I/I0), where I is the intensity of the sound and I0 is the reference intensity. The reference intensity is usually set at the threshold of human hearing, which is 10-12 watts per square meter.

## 2. How does adding decibels work?

When two or more sound sources are combined, the resulting sound level is not simply the sum of the individual sound levels. Instead, we use a logarithmic formula to add decibels. The formula for adding decibels is: LTOTAL = 10 log (10L1/10 + 10L2/10 + ... + 10Ln/10), where L1, L2, ... Ln are the individual sound levels in decibels. This formula takes into account the fact that our perception of sound is logarithmic and not linear.

## 3. What is the maximum decibel level that is safe for human hearing?

The maximum safe level of sound exposure for humans is 85 decibels. Prolonged exposure to sounds above this level can cause permanent hearing damage. The Occupational Safety and Health Administration (OSHA) has set regulations for safe noise exposure levels in the workplace, with a maximum exposure limit of 90 decibels for 8 hours per day.

## 4. Can decibels be negative?

Yes, decibels can be negative. Negative decibels indicate a sound level that is lower than the reference level. For example, if a sound is measured at -10 decibels, it means that it is 10 times quieter than the reference level. Negative decibels are commonly used to measure the sound reduction of noise-cancelling headphones or the sound insulation of buildings.

## 5. Is there a limit to how many decibels can be added together?

No, there is no limit to how many decibels can be added together. However, as the number of decibels increases, the resulting sound level may reach dangerous levels. It is important to consider the individual sound levels and their potential impact on human hearing when adding decibels together.

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