Telephone
device · 1876 · Electric age
Transmitting the voice over wires.
Inventors: Johann Philipp Reis, Elisha Gray, Alexander Graham Bell, Antonio Meucci.
What it is made of
- Microphone — has part. The handset microphone turns the voice into an electrical signal.
- Loudspeaker — has part. The earpiece reproduces the other person’s voice.
- Rotary dial — has part. A dial.
- Carbon microphone — has part. For a century, telephone microphones were carbon microphones.
Principles and materials it uses
- Telephone exchange — uses. Connecting subscribers.
- Copper — is made of. The wires and coils are copper.
- Bakelite — is made of. The body of classic telephones is Bakelite.
Where it is used
- Modem — is used in. It works over a telephone line.
- Fax — is used in. Transmission over a telephone line.
History: what it evolved from and what it influenced
- Electrical telegraph — evolved from. The telephone grew out of attempts to send several signals over telegraph lines (the “harmonic telegraph”).
- Mobile phone — evolved into. A mobile phone keeps the function of a telephone, replacing the wire with a radio channel.
- Video call — evolved into. A telephone with a picture.
- Hearing aid — evolved into. The first electric hearing aids were built from telephone components.
- VoIP — evolved into. Telephony over IP.
What it is a kind of
- Means of communication — is a kind of. A means of transmitting the voice.
- Intercom — includes. An intercom is a simple telephone between the door and the flat.