Solving Sound Wave Question: Energy Delivered to Eardrum

In summary, sound is detected when a sound wave causes the eardrum to vibrate, with a typical diameter of 8.4mm in humans. When spoken to in a normal tone of voice, the sound intensity at the ear is approximately 1 * 10^-6 W/m^2. Using the equation I = P/(4pi*r^2), the amount of energy delivered to the eardrum each second is calculated to be 5.54*10^(-11)W, taking into account the radius of the eardrum.
  • #1
stuti911
4
0

Homework Statement



Sound is detected when a sound wave causes the eardrum to vibrate. Typically, the diameter of the eardrum is about 8.4mm in humans. When someone speaks to you in a normal tone of voice, the sound intensity at your ear is approximately 1 * 10^-6 W/m^2. How much energy is delivered to your eardrum each second?

Homework Equations



I = P/(4pi*r^2)

The Attempt at a Solution



I tried using the equation and I got 2.20×10^−10 W as my answer, but it is wrong. I cannot understand why, because the question seems really simple.
Any help is appreciated, thanks!
 
Physics news on Phys.org
  • #2
stuti911 said:
I tried using the equation and I got 2.20×10^−10 W as my answer, but it is wrong. I cannot understand why, because the question seems really simple.
Any help is appreciated, thanks!
The diameter of the eardrum is about 8.4 mm. Which means the radius is half that. :wink:

[Edit: And welcome to Physics Forums!]
 
Last edited:
  • #3
yes, so if you take proper radius you will get the answer.
 
  • #4
yes, i did take the radius
this is my calculation:
(10^-6)*(0.00001764*4*pi) which gives my the answer above
can any of you try the question?
thanks!
 
  • #5
isn't the answer 5.54*10^(-11)W ?
 
  • #6
first of all, take eardrum as a circle, not sphere, and so use area as pi*r^2
 
  • #7
allright.. i got it!
thanks a whole bunch :)
 
  • #8
welcome Stuti...would you accept my friend request?
 
  • #9
supratim1 said:
welcome Stuti...would you accept my friend request?

Please keep personal messages out of public threads
 

Related to Solving Sound Wave Question: Energy Delivered to Eardrum

1. What is a sound wave?

A sound wave is a type of energy that travels through a medium, such as air or water. It is created by vibrations in the medium, which cause the particles to move back and forth, creating a disturbance that is perceived as sound.

2. How is sound energy delivered to the eardrum?

Sound energy is delivered to the eardrum through a series of processes. First, sound waves are collected by the outer ear and directed into the ear canal. The sound waves then cause the eardrum to vibrate, which in turn causes the tiny bones in the middle ear to vibrate. These vibrations are then transmitted to the inner ear, where they are converted into electrical signals and sent to the brain for interpretation.

3. What factors affect the amount of energy delivered to the eardrum?

The amount of energy delivered to the eardrum is affected by several factors, including the intensity of the sound wave, the distance between the source of the sound and the eardrum, and the characteristics of the medium the sound is traveling through. For example, sound waves travel more easily through air than through water, so more energy would be delivered to the eardrum in a similar scenario.

4. How is the energy of a sound wave measured?

The energy of a sound wave is typically measured in decibels (dB). This scale measures the intensity or loudness of a sound and is based on a logarithmic scale, meaning that a change of 10 dB represents a tenfold increase or decrease in sound energy. For example, a sound that is 80 dB is 10 times more intense than a sound that is 70 dB.

5. How does the human ear protect itself from excessive sound energy?

The human ear has built-in mechanisms to protect itself from excessive sound energy. For example, the muscles in the middle ear can contract to decrease the amount of sound that reaches the inner ear. Additionally, the inner ear has tiny hair cells that can become damaged by loud sounds, so the brain can also send signals to these cells to reduce their sensitivity and protect them from harm. This is why we may experience temporary hearing loss or ringing in our ears after being exposed to loud noises.

Similar threads

Intensity of sound wave and energy
    • Introductory Physics Homework Help
Replies
1
Views
1K
Max velocity of a vibrating loud speaker membrane given sound intensity
    • Introductory Physics Homework Help
Replies
4
Views
1K
Understanding MIT's applet on sound with Fourier coefficients
    • Introductory Physics Homework Help
Replies
3
Views
263
Sound Waves: Energy per second
    • Introductory Physics Homework Help
Replies
2
Views
1K
Calculating τ by knowing I is proportional to A^2
    • Introductory Physics Homework Help
Replies
8
Views
2K
Sound Wave Interference and Finding the Path Differences with Diagrams
    • Introductory Physics Homework Help
Replies
20
Views
2K
Physics behind the sound of guitars
    • Introductory Physics Homework Help
Replies
23
Views
2K
Audio interference of sound waves from two speakers
    • Introductory Physics Homework Help
Replies
19
Views
3K
I Sound power, amplitude, frequency, and decibels
    • Classical Physics
Replies
5
Views
474
Sound Wave Interference Problem
    • Introductory Physics Homework Help
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top