# Can you hear me now outside?

• sailordragonball
In summary, the conversation discusses how a recording engineer works in a soundproofed room that is 45.0 dB quieter than the outside. The sound intensity formula, I = (P/A) or I = (P/[(4)(pi)(r^2)]), and the dB formula, beta = (10 dB)(log(I/Io)), are mentioned, but there is confusion about how to use them. The conversation concludes with a question about the inverse function of the log function and the correct values to use for the reference sound intensity.

#### sailordragonball

A recording engineer works in a soundproofed room that is 45.0 dB quieter than the outside. If the sound intensity in the room is 1.30e-10 W/(m^2), what is the intensity outside?

I know this intensity formula ...

... I = (P/A) OR I = ( P / [(4)(pi)(r^2)] )

... and for dB ...

... beta = (10 dB)(log (I/Io)... I can't make sense of the 2 equations to know what to do next ... any ideas?

Do I substitute 45 dB for the 10 in the dB equation?

The outside sound is the more intense sound. The intensity inside is a fraction of the intensity of the outside sound such that the ratio gives a 45 dB difference. What is the value of beta, including its sign, if you take the outside sound intensity as the reference? What is it if you take the inside intensity as the reference?

I think I have to revisit working with logs ... it's been a while ... LOL - I'll get back to you though.

I came up with this ...

... 45 = 10 log ( I / 1e-10 ) = 10 log ( 1.3e-12 / 1e-10 ) ...

... does that sound right? LOL

sailordragonball said:
I came up with this ...

... 45 = 10 log ( I / 1e-10 ) = 10 log ( 1.3e-12 / 1e-10 ) ...

... does that sound right? LOL

No it doesn't. The 45 is in the right place, but where did 1e-10 come from? With a +45 on the left, the sound intensity in the room should be the reference I_o and the intensity outside the I. Waht is the inverse function of the log functiuon?

## 1. Can sound travel as far outside as it does inside?

Yes, sound waves can travel just as far outside as they do inside. However, the way sound travels outside may be affected by factors such as wind, temperature, and other environmental conditions.

## 2. Why does sound seem louder outside compared to inside?

Sound may seem louder outside because there are fewer objects for the sound waves to bounce off of, resulting in less sound absorption. In addition, outside noise levels may also be lower, making any sound seem louder in comparison.

## 3. Can sound travel further on a hot day compared to a cold day?

Yes, sound waves can travel further on a hot day compared to a cold day. This is because sound travels faster in warmer air, allowing it to travel further before dissipating.

## 4. How does the shape of the surrounding environment affect the way sound travels outside?

The shape of the surrounding environment can greatly impact the way sound travels outside. For example, sound waves may be reflected or absorbed differently depending on the presence of buildings, trees, or other objects in the area.

## 5. Can sound travel through different mediums outside?

Yes, sound waves can travel through different mediums outside, such as air, water, or solid objects. However, the speed and distance of sound travel may vary depending on the properties of the medium it is traveling through.