Discoveries Leading Up to Nobel Peace Prize for the Function of the Cochlea by https://padlet.com/courts22/74e7ju5lbrhcgkwu en-us 2023-02-24 16:40:03 UTC 2023-02-25 02:33:35 UTC hello@padlet.com 1961 Nobel Peace Prize Winner courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494144589 Georg von Békésy, Hungarian and American biophysicist, was born in Budapest, Hungary, on June 3, 1899. He studied chemistry at University of Berne. He later achieved his doctorate in Physics in 1923 at the University of Budapest after completing a military service. He worked at the Hungarian Post Office research laboratory working on  problems of long-distance telephone transmission. He spent much of his free time in the laboratory studying the ear as a component of the transmission system.

He learned to be handy with a file and a drill press at the Central Laboratory of Siemens, the autopsy rooms of the hospitals, and at mechanical workshops.

During 1939-1946, he was Professor of Experimental Physics at the University of Budapest. He left Hungary in 1946 for Sweden did research at the Technical Institute in Stockholm. In Sweden, he developed a new type of audiometer which was operated by the patient and had versatility.

In 1947 he went to the United States and worked at Harvard University in the Psycho-Acoustic Laboratory. He won multiple honors, including the Denker Prize in Otology (1931), the Guyot Prize for Speech and Otology of Groningen University (1939) and the Shambaugh Prize in Otology (1950). He was the recipient of the Leibnitz Medal of the Berlin Academy of Sciences (1937), the Academy Award of the Budapest Academy of Science (1946), the Howard Crosby Warren Medal of the Society of Experimental Psychologists (1955), and the Gold Medals of the American Otological Society (1957) and the Acoustical Society of America (1961). Honorary doctorates (M.D.) were conferred on him by the Universities of Munster (1955) and Berne (1959).

He was special because he devoted himself to one of the great unsolved problems in sensory physiology: how the inner ear converts vibrations into neural impulses. It was an enormously challenging problem because the cochlea is a tiny, complex, delicate structure encased in one of the hardest bones in the body.

"Physiologists had assumed that the tapering basilar membrane running the length of the cochlea was a bit like a harp, with elastic fibers of different length held under tension and resonating to different frequencies of sound. von Bekesy disproved that with the simple move of slitting the exposed membrane lengthwise and observing that the membrane was not stretched apart by the incision, but lay there intact. 

Other experiments involved sprinkling the transparent membrane with silver flakes and taking stroboscopic photographs of its motion as oscillations were applied to one end. von Bekesy discovered that sound vibrations transmitted to the cochlear fluid by the round window triggered a traveling wave along the length of the basilar membrane, and that because of the tapering shape of the membrane, the point of maxim amplitude varied with the fundamental frequency of the vibration. This was the basis for tonotopic or place coding, in which the hair cells showing the greatest response coded for the fundamental frequency of the sound. 

von Bekesy built a large mechanical model of the inner ear to explain and confirm his hypothesis of how it coded sound. The only thing he could not duplicate was the nerve supply, so he simulated it by placing his own arm along a long vibrating section. His 1961 Nobel Prize lecture was called “Concerning the Pleasures of Observing, and the Mechanics of the Inner Ear.”"

He was forced to retire in 1966, moved to Hawaii to continue researching, and passed in 1972. 

https://psychology.fas.harvard.edu/people/georg-von-b%C3%A9k%C3%A9sy

https://www.nobelprize.org/prizes/medicine/1961/bekesy/biographical/
]]> 2023-02-24 17:06:12 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494144589 Bartholomeo Eustachi Creates an Anatomical Treatise of the Ear, Among Many Other Anatomical Features courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494148976 Italian Anatomist, Bartholomeo Eustachi, prepared 47 anatomical drawings on copper plates in 1552. These plates include drawings of the skeleton and nerves. He used these  to describe the kidneys, vessels, and Eustachian valve.

Between 1561 and 1562, Eustachi wrote the Opuscula Anatomica which was a group of anatomical treatises on the kidneys (De renum structura), the organ of hearing (De auditus organis), the venous system (De vena quae azygos graecis dicitur) and the teeth (De dentibus)

Although he did not explicitly denote the cochlea, he did provide us with an anatomical account of what was believed to be the innerworkings of the ear: which obviously laid as the groundwork for future researchers and other doctors.

"The treatise on the ear provided the first post-classical account of the Eustachian tube, while the work on the azygos vein contained the first description of the thoracic duct and of the valvula venae in the right ventricle of the heart, the so-called "Eustachian Valve."

I chose this artifact as the first entry to provide a basis for all future research and medical discoveries on the ear. This was one of the first detailed anatomical drawings of the ear & he also was the first to describe the Eustachian tube (hence the name), which shows his contribution to the auditory field as well as medical field in general.


https://www.historyofinformation.com/detail.php?id=1865

https://link.springer.com/article/10.1007/s00381-019-04107-1#citeas



]]> 2023-02-24 17:10:11 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494148976 Gabriel Fallopius Describes the Cochlea courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494166463 Italian anatomist, Gabriel Fallopius, was famously known for discovering the fallopian tubes: the tubes that connect the ovaries to the uterus, but he also spearheaded a lot of progress in understanding the nerves in the head and face.

He was the first to both describe and name the cochlea, as well as describe the vestibular canals of the inner ear. He also coined the names of the “cavum tympani”, the tympanic cavity, the three ossicles, as well as the oval and circular window in the ear. He rediscovered the “canalis facialis”, the facial canal. "His name was also associated with the “hiatus canalis nervi petrosi maioris”, the opening of the major petrosal nerve canal, and the “ligamentum inguinale”, the inguinal ligament."

He wrote down his findings in his textbook, Gabrielis Fallopii medici Mutinensis Observationes Anatomicae, or Anatomical Observations of the Modena Physician Gabriele Fallopius. At this point in history, many medical professionals followed the theories and beliefs of Vesalius, but Fallopius made sure to correct observations of Vesalius that he believed to be wrong.

I chose this artifact given that it is the naming and discovery of the cochlea which is so relevant today and to the topic of Nobel Peace Prize being given to the person who highlighted the function of the cochlea. It is incredible that it took between the years of 1561 and 1960 to understand the function of the cochlea and demonstrates the complexity of the auditory system in the body.

https://gynecolsurg.springeropen.com/articles/10.1007/s10397-008-0453-3]]> 2023-02-24 17:23:34 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494166463 Thomas Willis Proposes Idea That Different Tones Can Excite Different Auditory Nerves courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494181333 In 1664, Thomas Willis, an English doctor, the Cerebri Anatome, a heavily influential text centered around the brain and nerves.

 In the eighteenth century, the general medical and scientific community agreed with his description of the brain and his famous "Circle of Willis" was published in the Bibliotheca Anatomica of 1774-1777.

Although he focused mostly on the brain, he also paid attention to the nerves in the ear and formulated a potential hypothesis of how hearing works. In 1672, he hypothesized that "different "tones" (species audibilis) may excite different fibres of the nervus acusticus."

Although he may not have discovered much when it comes to the cochlea, his hypothesis did provide a basis for further research into auditory processing. Not only was his hypothesis helpful for future research, I chose this artifact because he contributed to the field of medicine as a whole. We still learn about the Circle of Willis, and he is evidence of how neuroscience/medicine is so multifaceted.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC539424/

https://pubmed.ncbi.nlm.nih.gov/2242190/


]]> 2023-02-24 17:36:25 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494181333 Guichard Joseph Du Verney Creates Theory and Publishes Textbook About the Anatomy of the Ear courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494343814 Guichard Joseph Du Verney, a French anatomist, was the first to create a tonotopic theory of hearing that was based on the anatomical structure of the ear. He wrote his one an only medical textbook, Du Verney, in French which was then translated to the standard medical language: Latin. This textbook was revered as the accepted and accurate anatomy textbook of the ear for more than a century. 

"Du Verney considered the cochlea as the principal organ of hearing. He also stated that the vestibule and the semicircular canals were functional for hearing, a conclusion based on his observations that fishes and birds are able to hear and have a vestibule and semicircular canals but lack a cochlea. He believed that the tortuous passages of the labyrinth were like the tubes of trumpets that augment sounds passing into them and that this thereby aided the excitation of the nerve. Du Verney also was a subscriber to the classical theory of implanted air."

Interestingly enough, Du Verney has the correct theory, but incorrect observations of how the ear is organized tonotopically. "Du Verney’s observations were made on intact or dissected specimens but not on sectioned and stained material because microtone and staining were not introduced until the end of the eighteenth century," which suggest that he would have made more accurate observations if he had more advanced instruments that could have allowed him to fully measure the dimensions of the ear. Regardless of being incorrect, his theory remained the widely accepted theory of hearing until the late 1800s.

This artifact is important because it provides an early explanation of the understanding of the tonotopic organization of the ear. It also is interesting to see how scientists of the time used very simple technology or concepts to reach those conclusions. This paved the way for the overall understanding of auditory processes which led to the developments of today.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7062978/
]]> 2023-02-24 20:27:29 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494343814 Albrecht von Haller Asserts Low Frequency->Base & High Frequency->Apex of Cochlea in Publication courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494348258 Swiss anatomist and "Father of Modern Physiology," Albert von Haller, supported Du Verney's theory of tonotopic organization in the ear in his 1751 anatomical publication, Haller vA. First lines of physiology.

He asserted that low frequency tones stemmed from the base of the cochlea and that high frequency tones at the apex of the cochlea. In his publication, he describes the osseous lamina as "an indefinite number of cords, continually shortening in their lines (lengths of his so-called cords). By that means, they are adapted so that there is a greater variety of acute and grave sounds which vibrate sympathetically; the longest are at the base of the cochlea with the grave sounds, and the shortest near the apex with the acute sounds."

Further, he stated that the distinction of sounds depends on how fast the cochlea and acoustic nerve tremor since their movements happen after one another. 

This artifact serves as an example as to how von Haller furthered Du Verney's work by using it as a basis for his own findings. It demonstrates how scientists often further others research and reach new conclusions or more detailed work. It also is interesting how his findings supported an incorrect theory, but it was still believed widely by others. 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7062978/

]]> 2023-02-24 20:33:42 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494348258 Domenico Felice Antonio Cotugno Correctly Theorizes That Low Frequency->Apex and High Frequency->Base, But is Ignored courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494350622 Contradicting the prior 2 slides, Italian physician, Domenico Felice Antonio Cotugno, theorized that high frequency tones are mediated at the base of the cochlea with a continuum so that the low frequencies can be mediated at the apex of the cochlea. His theory of tonotopic organization was published in his 1761 dissertation.

Here below is an excerpt of his dissertation, explaining his understanding of the cochlea:

The necessity of the cochlea, in which there is a series of parallel and stretched strings, like in a tambourine, is quite evident. The cochlea keeps the nervous filaments it receives from the lamina spiralis together and keeps them parallel and of different lengths. I put the smallest of these strings at the base of the area (basilar membrane) right near the orifice of the scala tympani, where it is narrower. I put the longest ones at the small hook of the area. When a sound is generated, as in the case of the human voice, we may observe that, among all the strings of the tambourine, only one vibrates in unison with the sound; thus, within the cochlea, which is our tambourine, for every sound there is a corresponding and appropriate string that, by vibrating in unison, permits the soul to discriminate sounds. This fact probably explains why the cochlea does not exceed the length of two turns and a half, because in that area there may be an area long enough to get all the possible strings responding in unison to the sounds we hear. Therefore, we perceive the sound by means of the sept, we recognize the tones by means of the cochlea. 


Cotugno utilized resonance as the basis of his hypothesis of how the cochlea works. Aside from being the first to accurately hypothesize the tonotopic organization of the cochlea, he was also the first to demonstrate via observations of fresh anatomic specimens that the labyrinth is full of fluid and not empty with air. That finding contradicted and disproved the Greek theory that the ear had air inside. The findings about the labyrinth also contributed greatly to future understandings of the ear and cochlear function.  

However, although he was correct, Cotugno’s theory of tonotopic organization was ignored and it wasn't for several years that his correct theory became accepted in the mainstream. 

I enjoy this artifact because it's a good example of how the truth can easily be ignored or simply not believed. Had his theory been accepted at this moment and time, perhaps the discovery of the function of the cochlea would have happened earlier in time. Nonetheless, this is still an essential part of this timeline because it shows the progression of understanding of the ear, despite everyone's ignorance.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7062978/

]]> 2023-02-24 20:37:13 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494350622 Hermann Hemholtz Publishes Theory in Third Revision of His Textbook, "On The Sensations of Tone" courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494368333
About 100 years later, Cotugno is proven to have been correct when Hermann Helmholtz, German physician, publicizes the proper theory of tonotopic organization of the ear. 

Hermann Helmholtz reversed that prior belief that high tones were mediated at the apex and low tones at the base and theorized the view we hold today: high tones are mediated at the base of the cochlea and low tones are mediated at the apex. He did not create this theory in only one publication and revised his textbook, Die Lehre den Tonempfindungen als physiologische Grundlage für die Theorie der Musik, four times betwee 1857 and 1877. He reached his conclusions about the cochlea after learning of the measurements of the width of the basilar membrane that was publicized by zoologist, Victor Hensen. 

Helmholtz was a large fan of music and gave lectures on the foundation of music which directly affected his theories of resonancy of hearing and other works centered around the ear. His book mentioned above was originally published in German with 2 English editions: one in 1875 and one in 1954. 

To reach his conclusions about tonotopic organization, he also consulted the follow theories and findings: Ohm’s law of auditory analysis, Mueller’s doctrine of specific energy of nerves, and the anatomical discoveries of Corti and Hensen. Measurements by Hensen of the basilar membrane were most critical to the formation of Helmholtz’s resonance theory of hearing in the third edition. "Hensen observed that the basilar membrane was the more likely resonance structure in comparison with the pillar cells because it varies more markedly in size than the pillar cells: according to his observations, there is about a 12-fold increase in width of the basilar membrane from base to apex."


"The strongly vibrating parts of the membrane would, as has been explained in respect to all bodies which vibrate sympathetically, be more or less limited, according to the degree of damping power in the adjacent parts, by friction against the fluid in the labyrinth and in the soft gelatinous parts of the nerve fillet."


"Under these circumstances the parts of the membrane in unison with higher tones must be looked for near the round window, and those with deeper, near the vertex of the cochlea, as Hensen also concluded from his measurements. That such short strings should be capable of corresponding with such deep tones, must be explained by their being loaded in the basilar membrane with all kinds of solid formations; the fluid of both galleries in the cochlea must is also be considered as weighting the membrane, because it cannot move without a kind of wave motion in that fluid."

This is an amazing discovery that paved the way for accurate scientific improvements and understanding. This new theory of tonotopic organization was crucial for assessment of the cochlea and also is a great example of how scientists use other scientific work to build off their theories.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7062978/

https://whipplelib.wordpress.com/2021/08/31/200-years-of-hermann-von-helmholtz/
]]> 2023-02-24 21:01:15 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494368333 Alfonso Corti Discovers and Names the Sensorineural Organ of the Cochlea courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494378070 During 1850-1851, Italian anatomist, Alfonso Corti, was working at a laboratory at the University of Würzburg and was the first to describe multiple parts of the ear: the sensory epithelium, the spiral ganglion, the tectorial membrane, and the stria vascularis of the inner ear. During his time in laboratories and studying under professors, he also dealt with many cochleas. He learned methods of preserving cochleas and completed studies involving 200+ cochleas of both man and several animals.

He is also famous for naming the Organ of Corti: "Arranged on the surface of the basilar membrane are orderly rows of the sensory hair cells, which generate nerve impulses in response to sound vibrations. Together with their supporting cells they form a complex neuroepithelium called the basilar papilla, or organ of Corti."

Again, as previously mentioned, this is important because he helped to describe new parts of the ear that hadn't been studied. He also aided in understanding how to preserve the cochlea which would be helpful for future experiments and researchers.

https://pubmed.ncbi.nlm.nih.gov/3517746/]]> 2023-02-24 21:18:52 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494378070 Marie Jean Fluorens Researches Vestibular Organs Via Pigeons courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494380778 Deviating away from the cochlea itself but still focusing on the innerworkings of the ear, Marie Jean Fluorens, French physiologist and pioneer of anesthesia, was the first to experiment and observe the vestibular organs of the ear.

In 1825, he began research that was related to vestibular and otological disorders. His experiments on pigeons led to his first observations and hypotheses of the vestibular organs. 

He removed the semicircular canal in the pigeons and observed that once it was cut out, the pigeons would move their heads in odd ways. He also realized that when he cut the nerve fibers to these organs that hearing remained unaffected, but that hearing ceased when he cut out the basilar papila. Using these findings, he hypothesized that the semicircular canals of the ear are involved in maintaining posture and balance and that a lesion in the canals would result in imbalance and vestibular symptoms.

Although this isn't the cochlea, this artifact is important because an understanding of the ear as a whole is crucial to understanding the full function of the cochlea. This work proved to be helpful in the understanding of how the ear is connected to our vestibular sense which is extremely relevant to any part of neuroscience.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2117745/#:~:text=Flourens%20proposed%20that%20the%20semicircular,the%20previously%20described%20vestibular%20symptomatology.&text=Flourens%20was%20accepted%20as%20a,modern%20theory%20of%20brain%20function.]]> 2023-02-24 21:23:54 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494380778 Alfred M Mayer Publishes Work About Acoustics courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494385185
Alfred M Mayer, American physicist, conducted his work on acoustics and physics. 

He conducted many scientific experiments that included experiments showing "that the translation of a vibrating body causes it to emit waves differing in length from those produced by the same vibrating body when stationary; a method of detecting the phases of vibration in the air surrounding a sounding body, leading to his invention of the topophone; mode of measuring the wavelengths and velocities of sound in gases, resulting in the invention of an acoustic pyrometer; the determination of relative intensities of sound; five new methods of sonorous analysis for the decomposition of a compound sound into its elementary tones; the discovery that the fibrils of the antennae of the male mosquito vibrate sympathetically to notes which have the range of pitch of the sounds given out by the female mosquito; and the determination of the laws of vibration of tuning forks, especially in the direction of the bearing of these laws on the action of the chronoscopes that are used in determining the velocities of projectiles."

Around 1880, he created an electronic recording object that could determine the pitch number of any note, highlighting his success in the field of acoustics. 

 To measure the frequency of a tuning fork, Mayer attached a stylus to one of its prongs. He clamped the tuning fork securely next to a uniformly rotating cylinder around which smoked paper had been wrapped. When the tuning fork was set vibrating, the stylus inscribed a wavy line on the smoked paper. To measure the time, Mayer used a pendulum having a period of two seconds. The pendulum at a point in its swing tripped a switch, causing electricity to pass through an induction coil; the induction coil thus produced a spark every two seconds. The sparks burned spots on the smoked paper. The frequency of the tuning fork was the number of wave forms inscribed by the stylus during an interval of time measured, divided by the number of spots burned simultaneously on the smoked paper.

 If the tuning fork drew 500 waveforms on the paper during two intervals marked on the smoked paper, that is, in 4 seconds, then the fork's frequency was 500/4=125 cps. Mayer's apparatus provided a visual method of measuring frequencies and was important also in providing a record of the results.

One of Mayer's important achievements was to establish a quantitative relation between pitch and the duration of the residual sensation of a tone. Helmholtz had earlier found that the persistence of a sensation of a tone after the sound had ceased was longer for a lower pitch than for a higher pitch, but he had not succeeded in obtaining an exact quantitative formula for this relation. In 1874, Mayer succeeded in finding the formula on the basis of meticulous experiments. 

I included this artifact because I find it important to highlight work about acoustics and physics as well as just medical findings about the ear itself. Understanding the physics of sound and the ear itself is important to analyze the processing of sound in the ear, especially the cochlea. 

https://www.tandfonline.com/doi/full/10.1080/00033790.2012.692811
]]> 2023-02-24 21:32:19 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494385185 Revolutionary Technology Could Replace the Microphone Feature of the Cochlear Implant courts22 https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494386632 Envoy Medical Corporation, a hearing health company focused on providing innovative technologies across the hearing loss spectrum, announced in 2022 that the FDA approved its Investigational Device Exemption to begin a clinical trial with its fully implanted Acclaim® cochlear implant. 

The device has been advertised as such. "the Acclaim is unlike current commercially available cochlear implants due to the lack of any externally worn components and it was granted Breakthrough Device Designation in 2019 by the FDA. If approved by the FDA, the Acclaim would be the first-of-its-kind cochlear implant designed to be fully implanted and use the ear, rather than a microphone, to pick up sound."

The CEO of Envoy Medical stated, “we believe that a fully implanted cochlear implant may increase their use among millions of adults with significant hearing loss. This study is the first step in evaluating the safety and effectiveness of the fully implanted Acclaim cochlear implant, putting us closer towards potentially filling a large unmet need in hearing loss technology.”

There are between 1.5 and 4 million adults with hearing loss in the US that could use cochlear implants, but only 5% of eligible candidates use them. A common reason is due to the amount of external hardware required with the normal cochlear implant. The approval of this new technology could change the world of hearing impaired adults as they know it.

To test the device, surgeries were conducted by Colin Driscoll, MD, practicing neurotologist, professor of otolaryngology – head and neck surgery at Mayo Clinic, and principal investigator for this study. After a healing period, the Acclaim Cochlear Implant will be activated by Aniket Saoji, PhD, associate professor of otolaryngology – head and neck surgery at Mayo Clinic and co-investigator of the study. Both investigators serve on Envoy Medical’s Cochlear Implant Advisory Board.

This contemporary entry obviously revolutionizes the field of technology and otolaryngology. This development would be impossible without the work of von Bekesy and shows how fast technology can develop once science behind the body is understood.

https://hearinghealthmatters.org/hearing-technologies/2022/fda-approves-clinical-trial-of-first-fully-implanted-cochlear-implant/

https://www.businesswire.com/news/home/20221101005410/en/Envoy-Medical-Early-Feasibility-Study-of-Breakthrough-Fully-Implanted-Cochlear-Implant-Now-Underway
]]> 2023-02-24 21:35:10 UTC https://padlet.com/courts22/74e7ju5lbrhcgkwu/wish/2494386632