Wow, really interesting to have it spelt out that the sterocillia are sensory cells in the sense that they use ion channels to mediate presynaptic release of neurotransmitter. Though I thought that the explanations of vesicles as cars might be confusing for a lay audience
Technically, I don't think it is actually a digital to analog converter. Yes, the nervers are transmitting only single spikes, but there is a CONTINIUM related between the strength of auditory stimulus and the frequency of spikes. There is no quantization in the amplitude dimension. Further, there is NO quantization in the time dimension in that the individual spikes can happen at any time. Rather, this is like the first stage of a delta-sigma A/D converter producing the 1 bit bit stream where the number of bits is handled by the next phase. The next phase can be an arbitrary number of bits depending on how it is performed, but this is later parts of neurology. In many ways, the analog nature of the signal is still contained in the bit-stream in this case. The analogy is a bit flawed in that the first stage of a delta-sigma converter is clocked at a fixed rate producing some timing quantization where in this case it is not self clocked so there is no time dimension quantization.
This is directed worldwide. It's for the benefit of propagating knowledge to people who have trouble understanding English. A clear, slow pronunciation helps a lot.
Why would this evolve from nothing. I can see things that have to do with eating becoming more complex, Sight, mobility, but why would a organism go through all the trouble of creating this complex organic computer to hear what it did not know existed until it heard it. And that process is going on (running in the background) all the time for your entire life. It must have been one of the last things added to the senses.
On the evolution of mammalian hearing, you can probably find a video or article on how the auditory ossicles came to be. Because sound is pressure, we don't only listen with our ears, it can be felt in other tissues as well. You can think of hearing as a specialised form of the sense of touch. Airborne sound waves are oscillating changes in air pressure, but the way many of your other tissues are able to detect touch is also just a form of pressure sensing. Insects don't necessarily have ears, but they do often have external hair-like sensors which can be used for sensing sounds even though they would not have an audible "experience" like we do. If I have to differentiate between two signals of nearly identical pitches (even just 1 Hz), I find that they *sound* exactly the same and I can't tell the difference. But if I switch to monitoring my sense of *touch* instead, I notice the difference. It's just that our brain gives a different meaning and sensation based on which receptor cells you're receiving input on, even if the input is the same.
Wow, this is an incredibly intuitive explanation. Thank you Susan!
Susan you are a brilliant human and a legend. RIP Prince
Many thanks Susan! I like to think of the vesicles as Little Red Corvettes instead of Beetles ;)
Wow, really interesting to have it spelt out that the sterocillia are sensory cells in the sense that they use ion channels to mediate presynaptic release of neurotransmitter. Though I thought that the explanations of vesicles as cars might be confusing for a lay audience
Thank you for the wonderfully insightful video.
Which Berklee online course is this taken from?
The video is from Psychoacoustics in Music Production. Learn more here: berkonl.in/48JwaYf
excellent lesson thank you!
this was excellent, thank you
OMG I love her
Technically, I don't think it is actually a digital to analog converter. Yes, the nervers are transmitting only single spikes, but there is a CONTINIUM related between the strength of auditory stimulus and the frequency of spikes. There is no quantization in the amplitude dimension. Further, there is NO quantization in the time dimension in that the individual spikes can happen at any time. Rather, this is like the first stage of a delta-sigma A/D converter producing the 1 bit bit stream where the number of bits is handled by the next phase. The next phase can be an arbitrary number of bits depending on how it is performed, but this is later parts of neurology. In many ways, the analog nature of the signal is still contained in the bit-stream in this case. The analogy is a bit flawed in that the first stage of a delta-sigma converter is clocked at a fixed rate producing some timing quantization where in this case it is not self clocked so there is no time dimension quantization.
She speaks like a first grade teacher. I can’t get past it.
This is directed worldwide. It's for the benefit of propagating knowledge to people who have trouble understanding English. A clear, slow pronunciation helps a lot.
I thought that her voice sounds quite similar to Deborah Harry's ; crystal clear , gorgeous tone
Not everyone is as advanced as you are.
Why would this evolve from nothing. I can see things that have to do with eating becoming more complex, Sight, mobility, but why would a organism go through all the trouble of creating this complex organic computer to hear what it did not know existed until it heard it. And that process is going on (running in the background) all the time for your entire life. It must have been one of the last things added to the senses.
On the evolution of mammalian hearing, you can probably find a video or article on how the auditory ossicles came to be.
Because sound is pressure, we don't only listen with our ears, it can be felt in other tissues as well. You can think of hearing as a specialised form of the sense of touch. Airborne sound waves are oscillating changes in air pressure, but the way many of your other tissues are able to detect touch is also just a form of pressure sensing. Insects don't necessarily have ears, but they do often have external hair-like sensors which can be used for sensing sounds even though they would not have an audible "experience" like we do.
If I have to differentiate between two signals of nearly identical pitches (even just 1 Hz), I find that they *sound* exactly the same and I can't tell the difference. But if I switch to monitoring my sense of *touch* instead, I notice the difference. It's just that our brain gives a different meaning and sensation based on which receptor cells you're receiving input on, even if the input is the same.
And this is all by accident? Nature is incredible. A hidden powerful force must be behind this all. What it could be no one knows.
"A hidden powerful force must be behind this all." - nope. Our hearing is just the evolution of much simpler motion sensors in simpler verterbrates.