MayIKnow?

I thought we must be losing information due to the slow transmission velocity of nerve system as compared to the speed of sound. However, now it has been clearly explained that velocity of sound got nothing to do with what's we are hearing.

Good morning Studiot. I owe it to you guys for the patience. It is usually annoying and frustrating to put across a point to someone who has no fundamental knowledge of the subject he is talking about. I was worried that mod might lock me out for being a troll with those silly questions.. Anyway...I did notice your post #32 and I need time to understand them thoroughly which may take a few days. Meanwhile, my untrained mind do not see the relevance of filtering for the purpose of the original question. I am aware that we filter out most of the sound. My understanding is the process takes place in the brain not in the ear except for frequencies outside our hearing range. Going back to your red leaves analogy and supersnail; it would not explain if I am listening to a beautiful solo piano rendition in darkness. And let's say the noisefloor of the room is about 40dB due to the air conditioning system, you may hear them in the beginning but eventually your brain would ignore(filter out) those disturbing noise. In the example above, the supersnail would still pick all the leaves and put it in the basket and the brain would decide whether to pay attention to the red leaves or not. Am I correct? There are many occasions where what sounded as noise and under normal circumstance the brain would dismissive them as noise may somehow beginning to sound meaningful like here. We do not feel or hear out footfall or our clothes moving against our body. We only notice temperature if it goes up or down dramatically and so on. Can we take another example here? Let's say a gradual increase of 1kHz at 0.1dB per second. Normally, we couldnt detect a 0.1db change. So let's say we start playing 1 khz signal at 80dB and increase the volume gradually 0.1dB every second. So after 60 seconds the SPL would be at 110dB. 110dB is still below the pain threshold. Could we detect the change or not?

Thanks for the "correct" link. I did read StringJunky's link and was couldnt get passed the first paragraph with asking the same question again. What we hear as a pure tone may not sound like a pure tone as it was determined by period of nueron firing patterns. My nueron firing pattern maybe different from my dog.

That is still evolving when it comes to understanding how our ears work. Maybe this will interest you guys. Meanwhile, on reflection of what’s said in this thread, my understanding of this thread are as follows:- 1) Speed of sound is the speed of transfer movement of molecules to the adjacent molecules . 2) The speed got nothing to do with the oscillation of (air) molecules. 3) The frequency of the oscillation produces sound by creating sound pressure. 4) A slight vibration of 1e-8mm in the ear drum is detectable by us which is close to 0dB. 5) The eardrum membrane area is about 65 mm2. 6) The most the eardrum could travel when vibrating is not likely to exceed 0.5cm. ( I am guessing here because that’s the diameter’s of the eardrum) 7) Hair cells length is much smaller than the eardrum’s diameter. 8) When hair cells vibrate at 20kHz. The total distance in one second could not be more a few meters considering they are less than 1 mm lenght. ( Something is not right with this statement) 9) Total distance per frequency even at the max of 20kHz is still within the transmission speed of our fastest nerve system (120m/s) and therefore all information could be transferred to brain without loss. 10) However, I believe the neural transmission speed in our ears is about 8m/s only. Am I getting closer? At least now I am clear why the speed of sound is immaterial.

More than I ever hoped for. And I grateful to all of you guys. p.s. I did edit my above post explaining the reluctance.

I am aware from the beginning that the post was meant for me... ) Anyway, my "friend" did not make those comment. I only said "What I am told by someone whose expertise is in the field of psychoacoustics that the speed of nerve transmission limits our ability to hear above 20kHz. " Anyway, will try to get some clarification from him. Although, he did warn me that he knew very little about nerve function. It is not easy to approach a man in his late 80s or early 90s to ask for free lessons.

This will only work if the snails are back by the time the 31st load arrives and the duration of arrival of the load is the same as the duration for the snails to putting in the second bin and get back to the pile.

I cannot understand this statement based on experience. Let's say, I take a load of 1000 leaves from 10 meters away and throw it in bin asking 30000 snails to pick them up and put in in another bin. Do you expect them to accomplish this as fast as putting all the 1000 leaves directly to the second bin?

I am sorry I could not keep the pace. I am still thinking about post #26. I am the weakest link here. I may not expressing myself well and thank you Studiot for introducing Shannon theorem. Hope that would bring closer to understand how we really decode the sound in our ears. Regarding the the microphone analogy of Charon Y, does the ms abbreviation stand for millisecond? My m/s abbreviation stands for meter per second. I am thinking along a simple line; when there is a different speed on a highway there must be a bottleneck at the point where the speed slows. It is possible that all "vehicles" will get to the where it supposed to go but that would take a longer time. Sampling rate is not an issue here. It is more like mineral bottles in a conveyor where the bottleneck happens at the packaging section where the process goes on long after the conveyor machine stopped. However, I am beginning to see that the delay in neuronal speed is immaterial but I just trying to simplify the concept for my simple mind. I also learnt from the research conducted and published in paper titled Dogs Hearing (University of Nebraska) that dogs do hear same sound differently. I haven't read the papers but just skimping through the highlights it appears that it got more to do with the frequency bandwidth of dogs hearing. In my case, it is easier to ask question without having the slightest understanding of the basics. I just came across another new terminology for another delay in the hearing process; Axonal conduction delays. More fun time reading.

Same problem. Please try Chrome.

With respect, I am not referring to subjective perception of an individual. What I am told by someone whose expertise is in the field of psychoacoustics that the speed of nerve transmission limits our ability to hear above 20kHz. Scientifically, could this imply that whatever sound we hear is processed and playback in our head at own biological predetermined speed? Meaning what supposed to sound like a 33rpm record would sound like 10rpm to us. Since time is essentially the same then there must be significant amount of information discarded. Do I make sense?

We can't agree on this?

How about sound in when you are underwater? I have not experience underwater speakers in a swimming pool but to a person who claimed to have experienced it says they sound identical to the music that we hear in normal environment(air). This is another mystery like electricity that I will never able to understand. Even though electricity travels at almost the speed of the light the electrons hardly move. How and where these waves originates? Please don't answer this! Right now, I am interested to know if the slow conduction of our nerve system affects the tonal characteristics of the sound. Perhaps, 1 kHz may sound different to a cat since their nerve transmission is much faster than human.

Lost 45 minutes of reply to CharonY. The other reason why I think there must be significant amount of data lost due to the bottleneck is working of 24fps motion picture. While in nature our eyes receive light the whole time (second, in this context) the eyes only need slices of 24 frames in a second to reconstruct indistinguishable normal motion. Though we can see the lag or missing information of a rotating fan blades in a 24fps movie those information could be reconstructed by increasing the frame rate. The increase of frame rate can go one until the fastest event is captured and played back exactly how we would perceive them in nature. However, no matter how many frame rate we use, we will reach a point that our eyes will reach a point where it cant utilize the higher frame rate. This is the point why I think why our eyes and ears discard many information. If that is the case, what we are seeing and hearing may not look or sound as they appear to our brain. When it comes to sound perception, we cannot use the about example related to visual decoding because we cannot freeze sound like a picture. There must be continues stimulation for us to perceive sound. This stimulation comes in the form of sound pressure. Sound pressure is “Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average, or equilibrium) atmospheric pressure, caused by a sound wave –Wiki” . This pressure is the product of vibration of molecules in wave like motion. Speed of sound is determined by the speed of the waves travel through the medium. Finally these waves in the form of vibrating molecules hit our ear drum. 1) The speed they hit our ear drum would be 340m/s. 2) The millions of nerve cells would transfer the information with the speed of not more than 120m/s to the brain. 3) The distance of ear to brain doesn’t matter as the information gets slowed before reaching the brain. It doesn’t matter how many cells are undertaking the job to transfer the sound to the brain. 4) Sound is vibration and when the rate of vibration changes should it also change in the characteristic of the sound? On item (1) above, I am not sure if the speed of the sound and vibration of the molecules frequency are the same. I believe they must be lower. So if the vibration frequency is lower than what contributes to the speed of the sound? Thank you.

I do read quite a bit about ears and how they work. Anyway, a little knowledge can be a dangerous thing. I hope you would indulge my ignorance here. My understanding is the ears and eyes discard many "bits" before processing them. The best that our eyes could resolve is just about 7 to 10 bits. I believe our ears too fall within this range. Furthermore, once the signal reaches the ear it is transmitted via pulses of the hair cells nerve in in batches of 500Hz at max by each (something?). The other reason why I am interested in this point is because the best of the loudspeaker could only produce about 8 to 10 bit that is far less than the a recording made with 16 or 24 bit. It is also evident that we are in most cases unable to distinguish a 16/44.1 recording vs 24/96 which still far less than the resolution of actual sound. Doesn't this mean we are losing a lot of info before reaching the ears? I am trying to get the speed of molecules vibration which is measure in frequency to determine the speed of information hitting out ear drum. Meanwhile, correct me please if my thinking is that you cannot transfer information faster than the weakest link irrespective number of extra connections. It is like a bullet train reaching a cliff at 300 mph and the same bullet train miles before reaching the station splits each coach to a many different tracks but only travel at 100mph. Although, all of them going to end up at the bottom of the cliff but the speed of them differs. Unless, as already been explain in the earlier post, the spread doesn't matter. I have been told about this in another forum that music only evolved about 10 thousand years ago and evolution did not make our ears for listening music. However, I did not get a satisfactory answer when I pointed out there are many ancient artefacts of musical instruments dating as far as 400000 years and besides using our hearing sense for survival it also the first natures tagging to establish mother and newborn. In nature, the mother's voice is registered while the unborn is still in the womb. it take a little bit of sophistication to able to distinguish a mother voice among thousands of , say, noisy penguins.