A telephone was a communications device used on Earth. It was invented by Alexander Graham Bell. (TV: Father's Day)
The Doctor's TARDIS had a telephone both inside and out in several of its incarnations. The external one was simply a dummy, part of the police box disguise, and yet it was impossibly called at least twice. (TV: The Empty Child, The Bells of Saint John)
The miniaturised First Doctor and his companions tried to use Forester's telephone to alert someone to the dangers of DN6, but could not make themselves heard. However, this raised the suspicions of telephone operator Hilda Rowse enough to send her police constable husband Bert to investigate. (TV: Planet of Giants)
In 1968, the Sentience cut off all phone lines from Crook Marsham. (PROSE: Nightshade)
The Master fitted a extra-long phone cable to the Third Doctor's phone in his UNIT lab with the intention of using it (and the Nestene Consciousness' affinity with plastic) to kill the Doctor. (TV: Terror of the Autons)
Vardans were able to transmit themselves down telephone wires. (PROSE: Return of the Living Dad)
More specific types of telephone included:
- the mobile phone
- the superphone
- the TARDIS phone
- the smart phone
- the police box