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They can be connected to a light bulb or some other 'visible' means to indicate that someone it at the door.

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16y ago

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Why did Alexander Graham Bell work with deaf people?

Alexander Graham Bell followed the footsteps of his father, Alexander Melville Bell, as a teacher of the deaf. After graduating at the universities of Edinburgh and London, he spent his early years learning to educate deaf-mutes by using a system developed by his father. In 1872 he founded a school to train teachers of the deaf in Boston, MA. The school eventually became part of Boston University, where Bell was appointed professor of vocal physiology.


Was Alexander Graham Bell a philanthropist?

yes, he did a lot of work in helping the deaf.


Are Alexander Graham Bell's children deaf?

Alexander Graham Bell and his wife Mabel Gardner Hubbard had four children, two boys who died in infancy and two daughters... Elsie May Bell (1878 - 1864) and Marian Hubbard Bell (1880 - 1962). There is no indication that any of the children were deaf.


Were Alexander Graham Bell's daughter and wife deaf?

Bell had two daughters, but neither suffered from deafness. His wife Mabel was profoundly deaf, however, and Bell's mother had also been deaf-- one reason that motivated him in his work to develop a hearing aid that would restore some hearing to those who had lost it.


How much voltage is needed for a door bell to work?

12


Who were Alexander Graham bells family and what did they do?

bell's father,grandfather and brother had all been associated with work on elocution and speech,and both his mother and wife were deaf,profoundly influensing bell's life's work


Did Alexander Graham Bell do sign language?

While Alexander Graham Bell did work with the deaf community and advocated for oralism (the use of spoken language over sign language), he himself did not communicate using sign language. Bell believed that deaf individuals should integrate into mainstream society by learning and using spoken language.


Why did bell invent telephone?

Alexander Bell was not trying to invent the telephone . . . he was inventing a device that would help deaf people hear a little bit. He ran wires into a different room where helper was listening. It worked! The helper heard Bell from the other room. That started the idea that the device would work at a far distance from the person speaking.


Why did alexandre bell invented telephone?

Alexander Bell was not trying to invent the telephone . . . he was inventing a device that would help deaf people hear a little bit. He ran wires into a different room where helper was listening. It worked! The helper heard Bell from the other room. That started the idea that the device would work at a far distance from the person speaking.


What is Deaf literature?

Deaf Literature = a body of written stories, poems, songs and other genres which include Deaf characters, Deaf culture, Deaf identity and Deaf experiences in their work.


What group of people did Thomas Gallaudet work with?

the hearing impared or deaf


When did Alexander Graham Bell invent a way to help deaf people?

Alexander Graham Bell (March 3, 1847 - August 2, 1922) was an eminent scientist, inventor, engineer and innovator who is credited with inventing the first practical telephone.[N 1]Bell's father, grandfather, and brother had all been associated with work on elocution and speech, and both his mother and wife were deaf, profoundly influencing Bell's life's work.[2] His research on hearing and speech further led him to experiment with hearing devices which eventually culminated in Bell being awarded the first US patent for the telephone in 1876.[N 2] In retrospect, Bell considered his most famous invention an intrusion on his real work as a scientist and refused to have a telephone in his study.[4]Many other inventions marked Bell's later life, including groundbreaking work in optical telecommunications, hydrofoils and aeronautics. In 1888, Alexander Graham Bell became one of the founding members of the National Geographic Society.[5] Bell has been described as one of the most influential figures in human history.[6]