On this page, “db” means deafblind, so the b is not capitalized.”dB (decibel)” comes from the name of Alexander Graham Bell, the inventor of the telephone, so some might think it’s rude to write it in lowercase.
So I’d like to get away with it by saying “it’s unrelated,” but in fact this great inventor Graham Bell’s main job, or rather his family business, was an educator of the deaf, so it’s not unrelated to deafblindness.
You might wonder, “Why would an educator of the deaf be related to the telephone?” But Bell was inspired by the German scientist Helmholtz’s use of electromagnets to sound tuning forks, and was researching a “musical telegraph,” which suggested that if he lined up tuning forks of different frequencies and turned the electric current on and off like a piano with each vibration, it would be possible to send music by telegraph.
On the other hand, as a deaf educator, he wanted to show deaf people “sound,” so he would insert straw into the ear of a deaf person, pick up the sound on a soot-covered glass plate, and draw a wave pattern on it. These two ideas were combined to create the “telephone,” which converts sound into an electrical signal by combining a leather diaphragm that vibrates in response to wide-band sound with an electromagnet.
So the existence of deaf people was involved in the invention of the telephone.
And the idea of the “musical telegraph,” which allows multi-channel telegraphy by simultaneously transmitting the sounds of many tuning forks on a single wire, has now taken on a new form, FT8, which is a radio mode that even deaf people can enjoy. Bell himself may not have expected it to be used in this way.
Incidentally, this year marks exactly 150 years since Graham Bell invented the telephone in 1875.
(Reference: Toshikazu Kitayama, An Easy-to-Understand History of Science, http://ktymtskz.my.coocan.jp/S/telecom/tel2.htm)