The Importance of 8-20 kHz

[Keiv]

You guys better believe it, but a lot of people and including stupid audiologists tend to think that you don't need 8-20khz. But if you think about it, come on! Are we that stupid to think that mother nature want to waste energy on nonfunctional useless cells? NO WAY . And we gotta remember the number one rule, that mother nature designs our body to be lazy...so how is it possible that 8-20khz is useless if mother nature wants our body to conserve energy and be as lazy as possible.

So today I talked with a professor. And he said, the high frequency are extremely important in the spatial cues. The reason why people think they are useless is because they are unconscious of the fact that these 8-20khz are functioning everytime to help us identify where the sound is coming from (perception and localization of sounds). in other words, if they are DEAD, staarting from 20khz and going downward, we less sublety in our identification of where the sound is coming from. That's why you have people in their 70s who can't discriminate multiple speakers in a noisy room. Put them in a quiet room with one speaker, then can hear fine given that 250-5khz speech range is audible. So yeah!

He also suspects that these 8-20khz helps somehow protects the cochlea by assisting in something something, i don't know, but it is extremely important.

 

[Sjoerd]

And we gotta remember the number one rule, that mother nature designs our body to be lazy...so how is it possible that 8-20khz is useless if mother nature wants our body to conserve energy and be as lazy as possible.

Evolution is not some kind of road towards lazy mankind (or the perfect human). Nature just try's allot of things and....well, let's see what sticks. Since almost every born child has hearing up to and above 21000 kHz. For that reason allow you could assume that it must have some kind of survival advantage (so I agree with you).

But is it important to understand normal human speech? Probably not.

 

[Keiv]

Evolution is not some kind of road towards lazy mankind (or the perfect human). Nature just try's allot of things and....well, let's see what sticks. Since almost every born child has hearing up to and above 21000 kHz. For that reason allow you could assume that it must have some kind of survival advantage (so I agree with you).

But is it important to understand normal human speech? Probably not.

NO , I never said it is there for human speech , they are for localization of speech and spatial perception on a 3d dimensional plane, in other words without these high frequency you cannot localize speech, if there are multiple noise source, you won't be able to discriminate them. That's not their function, even way back then in the year 1000 B.C., there was no 8-20khz sound in the environment. Yet mother nature designs these 8-20khz, their function is not for us to hear them, they are to assist in the sound waves and deliver them, also to protect the cochlea (this part i didn't understand), and some other unknown function

and yes, read above when i said they are working all the time with speech, but we not cognizant of that, because we can't hear them!

 

[deanalewis]

Possibly the protection is so that the lower frequencies are further down the choclea an less prone to damage so mother nature put them there to act as a buffer.

Remember many wars have been caught without ear protection so how do we know the 8khz and above is not a more recent thing

 

[Keiv]

Possibly the protection is so that the lower frequencies are further down the choclea an less prone to damage so mother nature put them there to act as a buffer.

Remember many wars have been caught without ear protection so how do we know the 8khz and above is not a more recent thing

Ah, I was unsure of what you were saying, but you are saying that how do we not that 8-20khz didn't just appear in the year 1900 instead of 1000 b.c. hence you said "how do we know if it is not a recent thing right?" IF this is so, then that is not possible because biologically evolution takes over a 1000 years to change. So these 8-20khz are there at 1000 b.c., you get me?

No, they are not to buffer like that, I don't understand this part, because you can have a notch at 4khz, and 6khz and 8khz is perfectly 0.

And i do know there is a domino effect that once 20khz dies, 19khz is next to die, follow by 18khz....then 10khz,9khz..guess what? 8khz is next!, 7khz, 6khz.... is this true?

 

[Sjoerd]

NO , I never said it is there for human speech ,

I agree with you. I was trying to say that this is probably why doctors say 8-20 kHz is not important (and they are probably correct if it was only about understanding speech).

1 example. Older people tend to have more difficulty understanding conversations in noisy environments (loss of high frequency hearing could be the cull pit....)

 

[Keiv]

I agree with you. I was trying to say that this is probably why doctors say 8-20 kHz is not important (and they are probably correct if it was only about understanding speech).

1 example. Older people tend to have more difficulty understanding conversations in noisy environments (loss of high frequency hearing could be the cull pit....)

yes, this is what my point is about

 

[Sjoerd]

And i do know there is a domino effect that once 20khz dies, 19khz is next to die, follow by 18khz....then 10khz,9khz..guess what? 8khz is next!, 7khz, 6khz.... is this true?

High frequency tend to "go" first. But I don't think this is a domino effect. I think those hair cell are prone to damage simply because of their location in the cochlea.

 

[Keiv]

High frequency tend to "go" first. But I don't think this is a domino effect. I think those hair cell are prone to damage simply because of their location in the cochlea.

that is the domino effect! exactly! because the sound waves hit them first, so there are the first to bend,; and follow by the next lower frequency

 

[Keiv]

I have a question though, which is traditionally thought of as age-related loss or presbycusis, can we preseerve 8-20khz by having low noise exposure and a sound diet to prevent the nerve from degenerating/

 

[Sjoerd]

that is the domino effect! exactly! because the sound waves hit them first, so there are the first to bend,; and follow by the next lower frequency

Ok, I misunderstood you there. For me the domino effect is: 15 kHz can only go after 16kHz has gone. 16 can only go if 17 kHz is gone. This is not true for the in normal life. High frequencies just have a higher chance of going first, but it is not required (for a domino effect it is).

 

[Keiv]

Ok, I misunderstood you there. For me the domino effect is: 15 kHz can only go after 16kHz has gone. 16 can only go if 17 kHz is gone. This is not true for the in normal life. High frequencies just have a higher chance of going first, but it is not required (for a domino effect it is).

"For me the domino effect is: 15 kHz can only go after 16kHz has gone. 16 can only go if 17 kHz is gone"

yeah i think this is the case too.

 

[linearb]

I have a left side 14khz notch... 16-18khz is fine...

 

[deanalewis]

Keiv

Basically a child evolves from a single cell to a fully grown human we also find people who are savants.... What I'm saying is these frequencies probably are a new thing otherwise tinnitus would have been a bigger problem back thousands of years ago

 

[Nucleo]

Basically a child evolves from a single cell to a fully grown human we also find people who are savants.... What I'm saying is these frequencies probably are a new thing otherwise tinnitus would have been a bigger problem back thousands of years ago

Sound levels were also much less than the nonsense we have now.

 

[linearb]

Sound levels were also much less than the nonsense we have now.

yes, but infections of one kind or another are not new things by any stretch of the imagination, and hygienic understanding is a relatively new invention. So, there was probably less noise-induced cochlear damage, but as much / more virus/bacterial induced damage (which appears to be a pretty common vector for T).

 

[linearb]

Keiv

Basically a child evolves from a single cell to a fully grown human we also find people who are savants.... What I'm saying is these frequencies probably are a new thing otherwise tinnitus would have been a bigger problem back thousands of years ago

what makes you think that tinnitus wasn't a big problem thousands of years ago? There are a good number of historical accounts of T going back a long ways.

http://www.ncbi.nlm.nih.gov/pubmed/24333885

 

[bwspot]

Keiv

Basically a child evolves from a single cell to a fully grown human we also find people who are savants.... What I'm saying is these frequencies probably are a new thing otherwise tinnitus would have been a bigger problem back thousands of years ago

What a bs idea. Humans are designed to hear up to 20-21khz. No way this is something that just started. Leaves, ocean, wind. Just listen to It. Record It then listen without 8-20khz and it will sound like broken speaker. 8-20khz is where the most beautiful sounds live.

 

[deanalewis]

I doubt anything useful is above 12khz

 

[RaZaH]

wow, a lot of uninformed stuff going on in this thread ...not sure where to begin

 

[Telis]

I lost most of my hearing above 8khz, you would be surprised how much you use this portion of your hearing until it is gone.

 

[DogWhistle]

Forgive me if this question is only tangentially related to this topic. Since we know that human infants can hear up past 20 kHz, why don't all human adults have tinnitus in that range? My understanding is that the cochlear hair cells for those extreme, ultra high frequencies that only infants can hear, they die rapidly in the early years of a child's life. So how come the child doesn't get tinnitus?