Soundwave Intensity & Sound Level

In summary, the conversation discusses finding the sound intensity and sound level given the amplitude of a soundwave. It is mentioned that sound intensity is equal to power divided by amplitude, but without the power given, the problem seems impossible. However, it is then clarified that sound intensity can also be calculated using the sound pressure level formula, which is equal to 20 times the logarithm of the pressure divided by a reference pressure. Using this formula, the sound intensity is found to be 6.3*10^-12 W/m^2.
  • #1
tokuroka
6
0

Homework Statement


The amplitude of a soundwave is 5 X 10 ^-5 N/m^2
a) What is the intesity of the sound energy from this sound wave?
b) What is the sound level?

The Attempt at a Solution



Well I believe that Sound intensity is Power/amplitude. However, i only have the amplitude so.. does that mean that my problem is impossible?
 
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  • #2
L (dB) = 20*Log(P/Pref) = 10*Log(I/Iref)

According to the units, you are given the pressure (50 uN/m^2 = 50 uPa). Sound Pressure Level is 20*Log(P/Pref) where Pref is 20uPa. You get around 8 dB.

Sound Intensity = Sound Power / ***Area***. Now this 8 dB is just a ratio and is also equal to 10*Log(I/Iref) where Iref is 10^-12 W/m^2. You get 6.3*10^-12 W/m^2.
 
  • #3
OH. Thanks for your solution. I realize that I made a complete blunder now. So it was my formula...I get it now, but that does not bode well for my test results =|. Thanks again for your help.
 

1. What is the difference between soundwave intensity and sound level?

Soundwave intensity refers to the amount of energy that passes through a given area per unit of time. It is measured in watts per square meter and determines the loudness of a sound. On the other hand, sound level is a logarithmic measure of the sound's intensity relative to a reference point and is measured in decibels (dB). It is a more practical way of describing the loudness of a sound as it takes into account the sensitivity of human hearing.

2. How is soundwave intensity measured?

Soundwave intensity is measured using a sound level meter, which consists of a microphone that converts sound pressure waves into electrical signals and a display that shows the measured intensity in watts per square meter. The meter is placed at the location where the intensity needs to be measured and the reading is taken.

3. What factors affect soundwave intensity?

There are several factors that can affect soundwave intensity, including the amplitude of the soundwave, the distance from the source, and the medium through which the sound travels. The intensity decreases as the distance from the source increases, and it also decreases when the sound travels through a medium with high absorption or dispersion properties.

4. How does sound level relate to human hearing?

Sound level is a measure of how loud a sound is perceived by the human ear. The human ear can detect a wide range of sound levels, from the faintest whisper to the loudest rock concert. However, the human ear is not equally sensitive to all frequencies, which is why sound levels are measured in decibels, which takes into account the different levels of sensitivity at different frequencies.

5. Can soundwave intensity and sound level be harmful to humans?

Yes, high levels of soundwave intensity and sound level can be harmful to humans. Prolonged exposure to loud sounds can cause permanent hearing damage and lead to conditions like tinnitus. The Occupational Safety and Health Administration (OSHA) has set guidelines for maximum allowable exposure to different sound levels in the workplace to protect workers from potential harm.

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