Ear Ossicles Amplification: Synovial Fluid Present

[nishant34]

How do ear ossicles help in amplification even when there is synovial fluid present??

The ear ossicles help in amplification of received sound (right?). We know that the joint between the three ear ossicles is synovial joint. Therefore, we have synovial fluid to prevent friction.

This synovial fluid should also help to reduce the intensity of the sound that is transmitted forward.

So how do we say that the ear ossicles help in amplifying the sound waves??

 

[atyy]

http://www.ncbi.nlm.nih.gov/books/NBK11076/
http://www.scientificamerican.com/article.cfm?id=experts-how-do-the-hammer-anvil-a

 

[Darwin123]

The ear ossicles help in amplification of received sound (right?). We know that the joint between the three ear ossicles is synovial joint. Therefore, we have synovial fluid to prevent friction.

This synovial fluid should also help to reduce the intensity of the sound that is transmitted forward.

So how do we say that the ear ossicles help in amplifying the sound waves??

I am guessing here, based on physics. The bulk modulus of bone is much greater than the bulk modulus of water. The density of bone and water are more comparable. Therefore, the speed of sound in bone is probably much greater than the speed of sound in water.
Therefore, the speed of sound in the ossicles is probably much greater than the speed of sound in the synovial fluid. Thus, there is an impedance mismatch at the boundary between the ossicles and the synovial fluid.
Sound bounces off the boundary between ossicles and synovial fluid. So the ossicles serve as a pipe for transmitting sounds collected by the ear drums to the cochlea. In addition, the lever principle provides the amplification of the sound of the ossicles.
I think that the impedance mismatch between body fluids and hard bone is comparable to the impedance mismatch between air and body fluids.
Animals without ossicles often use other types of bone to get the sound to the cochlear. For instance, in some fish the air bladder collects sound. Some other skull bones lead the sound through the skull to the cochlear. In crocodilians, the jaw collects the sound and the jaw bone transmits the sound to the cochlear. There is usually some bone that leads the sound through the skull to the cochlear. Rarely does the path involve body fluid alone.

 

[nishant34]

THank you for your reply atyy and Darwin 123.

i really learned a few more new things. Thanks! :)

 

[LudusRex]

The ear ossicles, also known as the middle ear bones, play a crucial role in the process of hearing. They are responsible for transmitting sound waves from the outer ear to the inner ear, where they are ultimately converted into electrical signals that are sent to the brain for interpretation. The presence of synovial fluid in the joint between the ossicles may seem counterintuitive in terms of sound amplification, as it could potentially reduce the intensity of the sound waves being transmitted.

However, the ear ossicles are specifically designed to overcome this challenge. The three small bones, the malleus, incus, and stapes, work together to amplify the sound waves as they pass through the middle ear. This is achieved through a lever system, where the vibrations from the eardrum are transferred to the malleus, which then transmits them to the incus and finally to the stapes.

The presence of synovial fluid in the joint between the ossicles actually helps to facilitate this lever system, as it allows for smooth movement and reduces friction between the bones. This allows for efficient transmission of sound waves, ultimately resulting in amplification of the sound. Additionally, the unique shape and positioning of the ossicles also contribute to their amplification function.

In summary, while the presence of synovial fluid in the joint between the ear ossicles may initially seem like a hindrance to sound amplification, it actually plays a vital role in ensuring the efficient transmission of sound waves and ultimately contributes to the overall process of hearing.