Thomas Alva Edison was born on February 11th, 1847 in Milan, Ohio, USA. His father was Samuel Edison Jr and his mother was Mary Elliott. Edison was the youngest of seven children. When he was in primary school, Edison was considered a stupid student, and his attention was not concentrated. Because of his poor hearing, his academic performance and attendance rate were affected. At the age of 1, Edison was led out of school by his mother because she thought that the teachers in the school could not fully understand and cultivate his talent. After dropping out of school, Edison taught himself desperately. He wrote in his diary: "The Detroit Public Library became my refuge. I didn't just read, I read the whole library." Later, Edison worked as a newsboy for the Grand Trunk Railway Company in Port Huron, Michigan. By chance, Edison saved the life of the son of stationmaster J. H. MacKenzie from the railway. In order to repay Edison, MacKenzie asked Edison to learn telegraph transmission technology from him. Edison became interested in telegrams and began his career of invention.
Until today, people still don't know the exact nature and cause of Edison's deafness. Although it is generally believed that Edison suffered from middle ear infection or scarlet fever in his childhood, according to his childhood friend Paul Israd, Edison suffered from catarrhal inflammation and hearing loss, but there are no relevant medical records and materials in all Edison's files. Edison himself attributed his deafness to an ear injury caused by an accident, but paul Israel believed that Edison had frequent ear infections before he joined the railway work and his hearing was affected. Edison also recorded in his memoirs that his deafness began at the age of about 12. Without the pathological analysis of the neck bone, it is impossible to confirm the nature of Edison's deafness, but according to some data, Edison suffered from some degree of conductive deafness or mixed deafness. In the Edison Museum in Florida, there is a collection of the phonograph used by Edison. On the wooden shell of the machine, the tooth marks bitten by Edison are left. Edison listened to the sound of the phonograph clearly by biting the shell of the phonograph with his teeth, which showed that his bone conduction was better than air conduction, and his hearing impairment was bilateral. He wrote in his diary: "any sound that reaches my inner ear has been partially lost. Sound waves go directly to my brain through my inner ear. I have an extremely sensitive inner ear." But according to Ernest Stevens, the music director and pianist of Edison Studio, "The higher the pitch, the weaker the sound reaching his ears." Especially in his later years, this phenomenon is more obvious, indicating that Edison's deafness may have some components of sensorineural deafness. In a word, according to Edison's diary and his life records, Edison may suffer from deafness with bilateral conductive hearing loss. What is the most probable
cause of Edison's deafness? Differential diagnosis includes complications related to chronic otitis media, such as tympanic membrane perforation, ossicular chain corrosion or chronic middle ear effusion, cholesteatoma, and congenital ossicular chain fixation or otosclerosis.
There is no history of early deafness in Edison's family, and Edison's deafness develops slowly and progressively, so hereditary conductive deafness is unlikely. Similarly, untreated cholesteatoma has never had complications and is unlikely. Therefore, there are two possibilities for Edison's deafness, one is chronic otitis media, and the other is otosclerosis. The pianist Ernest Stevens described Edison's high-frequency hearing loss, which was consistent with cochlear otosclerosis. Edison himself also described hearing better in background noise (Webster's hearing error), and the slow development of deafness and bilateral onset are all in line with the characteristics of otosclerosis. However, otosclerosis in childhood is quite rare. Comparatively speaking, Edison's deafness is more likely to be caused by chronic otitis media, mainly based on the history of ear infection in childhood, accompanied by ear trauma, which may lead to perforation of tympanic membrane, or combined with interruption of ossicular chain, resulting in conductive deafness. According to Edison himself, a medical expert advised him to receive treatment to improve his hearing, but there is no data to confirm the exact time of what Edison said, and it is not clear whether the expert is an otologist or not and whether he intends to take surgery for Edison. At the end of the 19th century, otology has developed into a specialized branch, and the removal of purulent lesions of mastoid process, early tympanoplasty and orange bone resection have all been carried out. Edison was suggested to treat deafness, but there is indirect evidence that he may have chronic otitis media or otosclerosis.
Edison's earliest phonograph was produced in 1878. He called it a "speaking machine", which was a cylindrical machine made of tin foil. A tin foil was wound on the cylinder, and the cylinder was rotated by shaking the handle, and the stylus made a sound by crossing the tin foil. After continuous improvement, the phonograph finally developed into the motor-driven turntable used today, and the recording materials were also from tin foil, wax to vinyl plastic. In 1878, Edison Speaking Phonograph Company was founded, and the phonograph was widely welcomed by the public as soon as it came out. For the first time, people could hear wonderful performances without going to the theater, and even spend a few cents to listen to some favorite music in the store. In 1927 alone, 987, phonographs were produced and 14 million records were sold.
interestingly, Edison himself was not worried about his deafness at all. He even attributed his health to deafness. He said: "I have no doubt that my nerves are stronger and more perfect now than those stupid conversations and meaningless voices that normal people can hear." I have heard everything I need to hear. Some years ago, an expert came to see me and told me that he could improve my listening. I think he can do it, but I don't want him to try. " He also said: "Even when I proposed, my deafness helped me. It made me dare to get closer to her in order to hear what she said clearly." The remarkable difference between Edison and Alexander Graham Bell, 1847-1922) is that Bell devoted himself to helping the deaf. Bell invented the audiometer and compiled teaching materials for the deaf to encourage them to communicate orally. His efforts eventually led to the invention of the telephone. Edison was not only unwilling to receive treatment for deafness, but also not interested in the invention of hearing AIDS. The two men have overlapping fields in invention, but strangely, there is no great effort of communication and cooperation between them.
Edison was married twice. In 1871, he married Mary Stilwell and had three children. Mary died of typhoid fever in 1884. In 1886, Edison married his second wife Mina Miller and had three children. His second proposal was made by telegraph. "I taught my sweetheart Morse code, so I asked her by telegraph if she would marry me."
In p>1931, Edison died of uremia. At this time, the music industry has taken off. Although Edison himself may never have heard the sound of the phonograph he invented like a normal person, he knew the importance of his invention. Edison had long foreseen that this technology of recording sound would have a far-reaching impact on human society and culture, and "the inventor of the phonograph was deaf" has also become a quip widely handed down.