How Hearing Works - Interesting Video (plus video on hearing loss)

[SPFC]

Hi all,

Very interesting video showing how our hearing works:

This one is about hearing loss. I never knew the reason why high frequencies are the first to go.

 

[amirm]

Wow, these are by far the best explanation of our hearing I have seen. Mandatory watch for everyone!

I will move it to the reference area and promote it on the home page if there are no objections.

 

[Kal Rubinson]

Hi all,
Very interesting video showing how our hearing works:

Nice graphics but there is no mention of what the auricle or external auditory meatus do to the sound.
Small error: There is no amplification in the operation of the ossicles in the middle ear. There is no external power required and they function as a physical transformer to make an impedance transformation. Anyone want to guess why that is necessary?

 

[Blumlein 88]

When will they do the animation for audiophile ears? Hair cells that respond to at least 50khz.

It also occurred to me the one about hearing loss should show the hair cells reaction during heavy metal rock concerts when listening at the edge of the stage in full concert mode at about 130 db. Also instead of the smooth voice over they need Ivan L. Moody to do the narration of that one. Not recommended for good hearing health.

 

[Thomas savage]

Hi all,

Very interesting video showing how our hearing works:

This one is about hearing loss. I never knew the reason why high frequencies are the first to go.

Fantastic, completely missed this thread

Brilliant thanks so much

 

[SPFC]

Nice graphics but there is no mention of what the auricle or external auditory meatus do to the sound.
Small error: There is no amplification in the operation of the ossicles in the middle ear. There is no external power required and they function as a physical transformer to make an impedance transformation. Anyone want to guess why that is necessary?

Hmmm, not sure Kal, care to share with the less informed ones in this forum?

 

[Kal Rubinson]

Hmmm, not sure Kal, care to share with the less informed ones in this forum?

Sure. The entering sound energy medium is air and the inner ear is filled with endolymph (a liquid that has a much higher density than air) so, with no other mechanism in place, most of the energy would be lost in the transition. It is similar to what you experience hearing the sounds of the beach after you submerge in the surf.
The leverage of the ossicles and the high ratio of the area of the tympanic membrane (large) to that of the oval window (small) result in an increase in pressure at the oval window but at the expense of total force. This greatly reduces the loss (by about 22x referred to above and it particularly favors frequencies in the 3oo-5000Hz range due to the mechanics of the ossicles.

 

[Fitzcaraldo215]

Sure. The entering sound energy medium is air and the inner ear is filled with endolymph (a liquid that has a much higher density than air) so, with no other mechanism in place, most of the energy would be lost in the transition. It is similar to what you experience hearing the sounds of the beach after you submerge in the surf.
The leverage of the ossicles and the high ratio of the area of the tympanic membrane (large) to that of the oval window (small) result in an increase in pressure at the oval window but at the expense of total force. This greatly reduces the loss (by about 22x referred to above and it particularly favors frequencies in the 3oo-35000Hz range due to the mechanics of the ossicles.

Dr. Rubinson, as if we did not know before, you really know your stuff in this area.

 

[j_j]

I think it's a touch of a stretch to extend the eardrum response to 35000 Hz in a human. You have to consider the acoustic impedance of the air in front of the tympanum, especially at higher frequencies. Something has to move that mass.

A good model for eardrum performance at lower frequencies is a highpass filter, with a single 6db/octave rolloff below 700Hz.

 

[Kal Rubinson]

I think it's a touch of a stretch to extend the eardrum response to 35000 Hz in a human. You have to consider the acoustic impedance of the air in front of the tympanum, especially at higher frequencies. Something has to move that mass.

A good model for eardrum performance at lower frequencies is a highpass filter, with a single 6db/octave rolloff below 700Hz.

Ouch. That 3500hz was a typo which I just corrected. Thanks for catching it.

 

[j_j]

Ouch. That 3500hz was a typo which I just corrected. Thanks for catching it.

Yeah. I understand typos. I've been known a time or three.

 

[Kal Rubinson]

Yeah. I understand typos. I've been known a time or three.

The amazing thing is that it stood for a year and a half. On the Internet, where there's always someone looking to criticize, that's an eternity. It almost became false news.

 

[NorthSky]

Typo is my middle name. But then it is easily understandable for a French Kanadian.

Kal, you are correct; it is an eternity for not having been detected, and then not criticized with firm authority.

What are we thinking when we make typos?

 

[DonH56]

I just figured that's why Kal's the reviewer and I'm a simple country boy eng-uhn-ear...

 

[c1ferrari]

The amazing thing is that it stood for a year and a half. On the Internet, where there's always someone looking to criticize, that's an eternity. It almost became false news.

Perhaps, this is an argument that it was true...before it became false.