Inner Ear Hair Cell Regeneration — Maybe We Can Know More

[RB2014]

Wow, the news about SPI-5557 was back from 2009 to 2010. Thats a long time ago. So they are just getting started? There is not much information on what they are doing from what I can find.

I wonder if each time we try a new discovery a better one comes out and then replaces it, but the problem is that eventually we have to just jump in because waiting for a cure could take a long time if we do three clinical trials taking years for each one. There may also not even be a one cure as everyone has hearing loss for different reasons.

 

[beeeep]

But I have no idea or imagination how injected mesenchymal stem cells behave in case of damaged/overreacting hair cells (causing tinnitus, hyperacusis), because these hair cells are still available on the spot in the inner ear. So if someone has tinnitus/hyperacusis and no hearing loss and gets mesenchymal stem cells injected, it seems to me like a situation where you want to find a free seat in an overcrowded train with no free seats.

Actually, dead hear cells don't leave any free seats either for the stem cells.
They are replaced by supporting cells to protect the underlying neuronal endings.

(Basically, hair cells are surrounded by endolymph on one side and connect to the neuronal endings on the other side. The endolymph is toxic to the neuronal endings, hence loss of hair cells would cause much larger damage if they are just gone and the endolymph can get to the nerve).

That's why - in my opinion - causing the supporting cells to differentiate into hair cells is a much better approach than trying to inject more stem cells.

For the gory details on hair cell death, see this interesting but quite long article
Cochlear pathology, sensory cell death and regeneration

The section "Cell elimination and scar formation" at the beginning of the article gives a nice summary.

 

[Nick Pyzik]

Just done another frequency test and got upto 18,000hz but 19 and 20 are most certainly dead in my ears,heard nadda

What frequency test did you perform exactly, where did you perform, and how did you perform it?

 

[Nick Pyzik]

Actually, dead hear cells don't leave any free seats either for the stem cells.
They are replaced by supporting cells to protect the underlying neuronal endings.

(Basically, hair cells are surrounded by endolymph on one side and connect to the neuronal endings on the other side. The endolymph is toxic to the neuronal endings, hence loss of hair cells would cause much larger damage if they are just gone and the endolymph can get to the nerve).

That's why - in my opinion - causing the supporting cells to differentiate into hair cells is a much better approach than trying to inject more stem cells.

For the gory details on hair cell death, see this interesting but quite long article
Cochlear pathology, sensory cell death and regeneration

The section "Cell elimination and scar formation" at the beginning of the article gives a nice summary.

Hello Beeeep, can you describe to me the symptoms you are experiencing with your hearing and what caused these changes in the way you hear?

Thanks.

 

[bill 112]

What frequency test did you perform exactly, where did you perform, and how did you perform it?

No audiologist here will test past 10,000hz
A friend of mine who is experienced in the field done a custom test for me.
He played 900hz and increased it by 100hz all the way to 10,000hz.No hearing loss between 900-10,000hz.10db and 5db dip at 4000hz but that was really it.He then played at 11,12,13,14,15,16,17 and 18,000hz from a separate device at different volumes.These were played an increased in volume until I could hear them.Found it slightly harder to hear 17,and 18 in my left ear but could still hear them without the volume being increased that much.19 and 20 I couldn't hear at allIt wasn't the most accurate test I'll admit that but I wanted to know was I missing any frequencies so that's why we went up in 100hz increments.Good news is I heard all them clearly.Most audiologist won't test in 100hz increments so it was just a personal experiment.

 

[bill 112]

Stemcells may still be a viable treatment regardless of scar tissue formation in the Cochlea.I was reading a paper the other day about auditory nerve regeneration.Scientists using Stemcells injected a damaged auditory nerve with Stemcells,and well nothing happened.But when they placed the Stemcells on the scar tissue the cells were absorbed by the scar tissue and began repairing the nerve.If anything the scar tissue is vital in regeneration,it's like a homing beacon for the Stemcells.

 

[Nick Pyzik]

No audiologist here will test past 10,000hz
A friend of mine who is experienced in the field done a custom test for me.
He played 900hz and increased it by 100hz all the way to 10,000hz.No hearing loss between 900-10,000hz.10db and 5db dip at 4000hz but that was really it.He then played at 11,12,13,14,15,16,17 and 18,000hz from a separate device at different volumes.These were played an increased in volume until I could hear them.Found it slightly harder to hear 17,and 18 in my left ear but could still hear them without the volume being increased that much.19 and 20 I couldn't hear at allIt wasn't the most accurate test I'll admit that but I wanted to know was I missing any frequencies so that's why we went up in 100hz increments.Good news is I heard all them clearly.Most audiologist won't test in 100hz increments so it was just a personal experiment.

If you can't find an audiologist who performs a test that gives you the whole audio frequency spectrum, you can basically perform one on yourself. Using a sine sweep, you can simply figure out which frequencies you hear and which ones you don't. The thing is, the correct auditory nerve fibers are what amplify each frequency into our brain to allow us to hear that sound much louder and clearer. So as long as you "pick up" each frequency as each one goes by, that clearly indicates that those hair cells are intact right? The more in-going nerve fibers you have on each inner/outer hair cell, the better you'll be able to pick those frequencies up. Our hair cells are so incredibly microscopic that it really doesn't matter how many you have to have the ability to process sound much louder. Sound wave frequencies are all "heard" in our brain through the nerve fibers of the auditory nerve even though they are picked up by the hair cells. As I've also explained many times in different posts, we lose in-going nerve fibers through loud noise//aging factors and are replaced by out-going nerves which don't allow us to clearly and process sound loudly in our brain. Which is what I believe has happened to you and what causes what we call "Tinnitus".

But please give this frequency test a try. It's the full spectrum. You can use headphones or even play it from your laptop/computer speakers. Please make sure that there are no other sounds to distract your brains processing abilities when it is played, otherwise you will most likely miss the higher frequencies. I just have a feeling that you have not damaged any of your hair cells and just the auditory nerve fibers of your hearing. I can back that up because of how many incredibly loud shows I've played in bands, how much music I've listened to, how many jam sessions I've had, and the amount of other types of loud noises that have been involved in my life, yet when I've performed my own hearing frequency tests, I can still hear from 200 hz to 20,000 khz. Also to include the fact that so much emotional and physical changes have happened to me over the past months that made it feel like I literally did lose the hair cells of my hearing. But I've performed the test on this site as of lately and I can still hear the whole thing besides all the changes in the way I hear. With all the awful things going on, it's very amusing.

What exactly caused your hearing issues again Bill? Was it acoustic trauma?

Here is a link to the frequency test. Perform the Logarithmic one.
Link: http://www.audiocheck.net/testtones_sinesweep20-20k.php

 

[tomytl]

Some news concerning hearing and stem cells:
http://www.sheffield.ac.uk/research/impact/stories/stem-cell-deafness-cure-1.567208

 

[bill 112]

If you can't find an audiologist who performs a test that gives you the whole audio frequency spectrum, you can basically perform one on yourself. Using a sine sweep, you can simply figure out which frequencies you hear and which ones you don't. The thing is, the correct auditory nerve fibers are what amplify each frequency into our brain to allow us to hear that sound much louder and clearer. So as long as you "pick up" each frequency as each one goes by, that clearly indicates that those hair cells are intact right? The more in-going nerve fibers you have on each inner/outer hair cell, the better you'll be able to pick those frequencies up. Our hair cells are so incredibly microscopic that it really doesn't matter how many you have to have the ability to process sound much louder. Sound wave frequencies are all "heard" in our brain through the nerve fibers of the auditory nerve even though they are picked up by the hair cells. As I've also explained many times in different posts, we lose in-going nerve fibers through loud noise//aging factors and are replaced by out-going nerves which don't allow us to clearly and process sound loudly in our brain. Which is what I believe has happened to you and what causes what we call "Tinnitus".

But please give this frequency test a try. It's the full spectrum. You can use headphones or even play it from your laptop/computer speakers. Please make sure that there are no other sounds to distract your brains processing abilities when it is played, otherwise you will most likely miss the higher frequencies. I just have a feeling that you have not damaged any of your hair cells and just the auditory nerve fibers of your hearing. I can back that up because of how many incredibly loud shows I've played in bands, how much music I've listened to, how many jam sessions I've had, and the amount of other types of loud noises that have been involved in my life, yet when I've performed my own hearing frequency tests, I can still hear from 200 hz to 20,000 khz. Also to include the fact that so much emotional and physical changes have happened to me over the past months that made it feel like I literally did lose the hair cells of my hearing. But I've performed the test on this site as of lately and I can still hear the whole thing besides all the changes in the way I hear. With all the awful things going on, it's very amusing.

What exactly caused your hearing issues again Bill? Was it acoustic trauma?

Here is a link to the frequency test. Perform the Logarithmic one.
Link: http://www.audiocheck.net/testtones_sinesweep20-20k.php

I'm going to do this now but these frequency sweeps scare meI've don't them before but I'm usually in a lot of pain even on the lowest volume.Thanks Nick

 

[RB2014]

Some news concerning hearing and stem cells:
http://www.sheffield.ac.uk/research/impact/stories/stem-cell-deafness-cure-1.567208

Wow, awesome find. I wish i were a gerbil. 46% increase is huge. This really is looking more and more promising as time goes on.

I'm going to start saving up for a gerbil costume and a trip to the UK. Then I will report back my experience to the group.

 

[Nick Pyzik]

Some news concerning hearing and stem cells:
http://www.sheffield.ac.uk/research/impact/stories/stem-cell-deafness-cure-1.567208

Unfortunately the information on the page you've linked has been on that site for a while. Not very long but I remember reading about Rivoltas work and the information on this page back in October of 2015. I'm not sure why they "updated" it yesterday but without much more added to it. It's basically a carbon copy of what was there before.

 

[bill 112]

If you can't find an audiologist who performs a test that gives you the whole audio frequency spectrum, you can basically perform one on yourself. Using a sine sweep, you can simply figure out which frequencies you hear and which ones you don't. The thing is, the correct auditory nerve fibers are what amplify each frequency into our brain to allow us to hear that sound much louder and clearer. So as long as you "pick up" each frequency as each one goes by, that clearly indicates that those hair cells are intact right? The more in-going nerve fibers you have on each inner/outer hair cell, the better you'll be able to pick those frequencies up. Our hair cells are so incredibly microscopic that it really doesn't matter how many you have to have the ability to process sound much louder. Sound wave frequencies are all "heard" in our brain through the nerve fibers of the auditory nerve even though they are picked up by the hair cells. As I've also explained many times in different posts, we lose in-going nerve fibers through loud noise//aging factors and are replaced by out-going nerves which don't allow us to clearly and process sound loudly in our brain. Which is what I believe has happened to you and what causes what we call "Tinnitus".

But please give this frequency test a try. It's the full spectrum. You can use headphones or even play it from your laptop/computer speakers. Please make sure that there are no other sounds to distract your brains processing abilities when it is played, otherwise you will most likely miss the higher frequencies. I just have a feeling that you have not damaged any of your hair cells and just the auditory nerve fibers of your hearing. I can back that up because of how many incredibly loud shows I've played in bands, how much music I've listened to, how many jam sessions I've had, and the amount of other types of loud noises that have been involved in my life, yet when I've performed my own hearing frequency tests, I can still hear from 200 hz to 20,000 khz. Also to include the fact that so much emotional and physical changes have happened to me over the past months that made it feel like I literally did lose the hair cells of my hearing. But I've performed the test on this site as of lately and I can still hear the whole thing besides all the changes in the way I hear. With all the awful things going on, it's very amusing.

What exactly caused your hearing issues again Bill? Was it acoustic trauma?

Here is a link to the frequency test. Perform the Logarithmic one.
Link: http://www.audiocheck.net/testtones_sinesweep20-20k.php

Yes I believe so,started randomly one day and was then worsened by noise.I done that sweep,didn't really notice any dips,just a clean sweep through until it wasn't audible anymore?Ive no idea what this means though

 

[Alue]

So, I just did a ultra high frequency hearing test today. I had tried to see what I can hear with speakers at home but it seemed to cut off at 13kHz or so.

The test I had today was really strange, I could hear the higher frequencies played at a low volume, but they did not sound tonal, instead the sound had this aura to it. It's hard to describe, not anything I can really replicate, but it sounded like this band of frequencies. When I test at home I can't even hear it, but my speakers are not calibrated.

 

[Nick Pyzik]

Yes I believe so,started randomly one day and was then worsened by noise.I done that sweep,didn't really notice any dips,just a clean sweep through until it wasn't audible anymore?Ive no idea what this means though

Although we have no way to actually see our hair cells, from the information I understand, what I've researched, and what I've been experiencing, it has to mean that you have not damaged any of your hair cells and it's auditory nerve fiber damage that's causing any sort of hyperacusis, tinnitus, or hearing loss you are experiencing. If you went through that sweep and there were large areas of no audible sound, then that clearly means you have damaged regions of hair cells in your cochlea. But you didn't. So that means there is no damage present in the cochlea.

 

[bill 112]

Although we have no way to actually see our hair cells, from the information I understand, what I've researched, and what I've been experiencing, it has to mean that you have not damaged any of your hair cells and it's auditory nerve fiber damage that's causing any sort of hyperacusis, tinnitus, or hearing loss you are experiencing. If you went through that sweep and there were large areas of no audible sound, then that clearly means you have damaged regions of hair cells in your cochlea. But you didn't. So that means there is no damage present in the cochlea.

Hmmmm makes sense I suppose,I just listened and heard the tone start,after it started it just swept through the frequency range and I didn't notice any dips or areas of inaudible sound,I heard it all the way through till the end or where my hearing cuts off.Interesting indeed

 

[Aaron123]

Some news concerning hearing and stem cells:
http://www.sheffield.ac.uk/research/impact/stories/stem-cell-deafness-cure-1.567208

I am assuming this is a new study since nothing like this shows up on pubmed for Dr. Rivolta, but what's really frustrating is that they provide no information about where and when the paper is/was published. Most news releases provide at least that much information. He has a 2015 paper where he and his co-authors propose a gerbil model for studying aminoglycoside-induced hair cell loss (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4441107/) so it is possible that he has a new paper using gerbils. I've contacted Sheffield and will post if/when I hear back.

In seeing if I could find the paper, I came across the 14th International Conference on Cochlear Implants next month in Toronto (http://www.acialliance.org/?page=CI2016) The basic science symposium looks interesting.

 

[tomytl]

I am assuming this is a new study since nothing like this shows up on pubmed for Dr. Rivolta, but what's really frustrating is that they provide no information about where and when the paper is/was published. Most news releases provide at least that much information. He has a 2015 paper where he and his co-authors propose a gerbil model for studying aminoglycoside-induced hair cell loss (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4441107/) so it is possible that he has a new paper using gerbils. I've contacted Sheffield and will post if/when I hear back.

In seeing if I could find the paper, I came across the 14th International Conference on Cochlear Implants next month in Toronto (http://www.acialliance.org/?page=CI2016) The basic science symposium looks interesting.

Thank you for the provided link.
Yes it's true, the article released at the 11th of april doesn't include some really new stuff.
I just hope, they made some further progress.

Some other research project like Roche's
Inception 3 is also very silent, I guess they aquired some stuff from Stanford's research
but I'm not sure.
http://www.inceptionsci.com/companies/

 

[Alue]

Good video put out by Auris:
http://media.corporate-ir.net/media_files/IROL/25/253572/webcast/Marlies Knipper v2.mp4

 

[tomytl]

Does someone know what research Pfizer is doing? Are they partnering with a biotech?
I just read following:
Pfizer ($PFE) is in early-stage development of a treatment that improves the function of hair cells that impact hearing

 

[tomytl]

Interesting read about current research and near term future:
http://cen.acs.org/articles/94/i11/Drugmakers-tackle-hearing-loss.html

 

[Reinier]

Do people realise that "home made audiograms" are far from accurate? A headphone or speaker system is everything but accurate. Just look at the frequency response of headphones and speaker systems. Let alone speakers from computers. It is a course way of telling if you can hear something. It will not tell you if have a dip in your hearing. It can easily be 5 dB off or more. Especially at frequency's higher than 10 kHz. I would imagine that headphones used for hearings tests (and especially the tests that go higher than 10kHz) are expensive and accurate. (And the amplifier feeding it needs to be considered too). What is the use to go up in increments of 100Hz when your headphone is not accurate.
Not directly related to "inner hear cell regeneration", but I thought I mention it.

 

[RB2014]

Agreed with Reinier. Something as simple as a 10db loss at 8k could be enough reason to have T. You really can't measure that unless you get a complete hearing test done.

Now being able to hear up to 18k. Wow. At 42 I have 50db loss below and an 80-100 db loss above 1k and even more at 2k, 4k, 8k. Basically means without hearing aides I can't hear above 1k unless its really loud and even then I can only get up to 1.5k or so. Even with my really powerful hearing aides I only go up to a little over 3k. I know why I have T and I get to listen to every frequency on the spectrum all mashed together to form one tone, but sometimes I get a symphony playing in my head.

My brain did do an incredible job though for 41 years blocking the T out even with extreme hearing loss and if it wasnt for my last bout with anxiety/stress I probably wouldn't be on these forums.

 

[Reinier]

Now being able to hear up to 18k.

Yes. Same with me. 18Khz. Wow
Something I can only dream about.

 

[Alue]

Do people realise that "home made audiograms" are far from accurate? A headphone or speaker system is everything but accurate. Just look at the frequency response of headphones and speaker systems. Let alone speakers from computers. It is a course way of telling if you can hear something. It will not tell you if have a dip in your hearing. It can easily be 5 dB off or more. Especially at frequency's higher than 10 kHz. I would imagine that headphones used for hearings tests (and especially the tests that go higher than 10kHz) are expensive and accurate. (And the amplifier feeding it needs to be considered too). What is the use to go up in increments of 100Hz when your headphone is not accurate.
Not directly related to "inner hear cell regeneration", but I thought I mention it.

I agree, it's not calibrated, but I've done some up to 8kHz hearing tests with headphones on my cell phone. I've had many hearing tests in sound booths over the past 3 months and the numbers match. I think aliasing becomes more of a problem in the higher frequencies. I just find it weird that I was able to hear the high frequencies (although very distorted) in the hearing booth, but I cannot hear them at all with home speakers/headphones.

 

[Aaron123]

Interesting read about current research and near term future:
http://cen.acs.org/articles/94/i11/Drugmakers-tackle-hearing-loss.html

Thanks for posting this. I think Decibel is a company to keep an eye on, but I hadn't seen anything from them since the October 2015 announcement regarding Third Rock. The initial investment and their hiring goals are promising - and they are hiring: https://decibeltx.com/careers/

I heard back from Sheffield regarding the earlier "research story". The information in that story comes from a 2012 paper http://www.nature.com/nature/journal/v490/n7419/full/nature11415.html Disappointing that it is not something new.

 

[tomytl]

Highly interesting reading! Nearly everyday some news about the inner ear, that's great!
http://eatocklab.tumblr.com/current_projects

 

[jdjd09]

Highly interesting reading! Nearly everyday some news about the inner ear, that's great!
http://eatocklab.tumblr.com/current_projects

@tomytl , you sure they won't have a cure in next 10 or so years? It just seems like there is a lot of interest in hearing loss cures? Or maybe I'm imagining things. IDK.

 

[tomytl]

@tomytl , you sure they won't have a cure in next 10 or so years? It just seems like there is a lot of interest in hearing loss cures? Or maybe I'm imagining things. IDK.

Hi,
nobody knows if/when there will be a cure for inner ear problems.
But what I know from my ear-journey since 2003, that there has been a lot lot more of research and pharma companies are arround and nearly every day or week we can read the word "hair cell regeneration" somewherebin the news.
Also some pharma companies/biotechs has a curable candidate in their pipeline.
Maybe we don't need real hair cell regeneration first, maybe there is another way to enhance hearing.
I think, it's good to be full of hope while having realistic expetations. There won't be a pill out of nowhere.
Maybe if the field of regenerative medicine reaches a standard for some different applications, maybe then new treatments might come faster.
But I'm just a layman with 13 years of search experience and I already read 10 years ago headlines like " a new cure for hearing loss is on the horizon".... so 10 years later, Genvec was/is on the horizon....

 

[Reinier]

I just find it weird that I was able to hear the high frequencies (although very distorted) in the hearing booth, but I cannot hear them at all with home speakers/headphones.

Can you describe the distortion?
I remember form when I was able to hear fine, my high frequency speakers in a three way speaker system struggled with higher frequency's. Just playback pure sinus tones, the problems started at 8 kHz. They were not cheap speakers!
They would playback higher frequency's, but started to attenuate in comparison with frequencies lower than approximately 8-9kHz. Get a speaker system flat from 50-15000 Hz is only for the very high quality speaker systems.
Than I am discounting acoustics of your listening room that will make a mess of the speaker systems "flat" response.

 

[Reinier]

you sure they won't have a cure in next 10 or so years?

It would help if not so much energy and money is spend on research like this.
medicalnewstoday.com/articles/308875.php "Going to a rock concert? Remember to take your earplugs"
and: medicalnewstoday.com/releases/308827.php "Middle-aged adults with hearing loss have substantially higher health care costs".
If research was concentrated more on an actual cure, that would be wonderful.
But I agree with @tomytl (although I "only" suffered from NIHL for almost a year) it looks like hearing is relatively "hot".
Let us just hope it is not "looks like", but more a statement like: " hearing research is on the increase". Perhaps 2016 will be a good year.