What did Bell invent?

Everyone has heard of Bell, but do you know what Bell invented?

The Life of the Characters in Bell's Works

First of all, let's introduce Bell's life. 1March 3, 847, Alexandria? Graham. Bell was born in Edinburgh, Scotland, and received primary education there.

Bell 1870 immigrated to Canada and arrived in the United States one year later. He became an American citizen on 1882. Bell himself is an acoustic physiologist and a deaf-mute language teacher. Before him, the German Philip? Les once invented a telephone, but the sound transmission effect was too poor to be used in practice. On March 1876, Bell and his colleagues tested the world's first available telephone.

Bell's invention

Then look at his invention. Bell invented the telephone. He connected two transmitters and receivers with the same structure and the diaphragm on the electromagnet with two wires. First of all, he realized both ends of the conversation. But the call distance is short and the efficiency is low. Carbon microphone appeared in 1878, which greatly improved the efficiency of telephone microphone and the structure of receiver.

In addition, Bell also invented an instrument for measuring hearing, an instrument that can be used to find metals in the human body and other inventions.

As you can see, Bell invented the first working telephone in the world, and also invented an instrument for measuring hearing, an instrument that can find metals in the human body. Do you know that?/You know what?