question: Hvornår kom den første touchtonetelefon ud...?
answers.text: 18. november 1963
context: Push-button telephone
  Western Electric eksperimenterede allerede i 1941 med metoder til at bruge mekanisk aktiverede rørblade til at producere to toner for hvert af de ti cifre, og i slutningen af 1940'erne blev denne teknologi afprøvet i praksis i et nr. 5 Crossbar-omskiftesystem i Pennsylvania. Men teknologien viste sig at være upålidelig, og det var først længe efter transistorens opfindelse, at trykknapteknologien blev modnet. Den 18. november 1963, efter ca. tre års afprøvning hos kunderne, introducerede Bell System i USA officielt DTMF-teknologien (dual-tone multi-frequency) under sit registrerede Touch-Tone-mærke. I løbet af de næste par årtier erstattede touch-tone-tjenesten den traditionelle teknologi med pulseopkald, og den blev i sidste ende en verdensomspændende standard for telekommunikationssignalering.
answers_en.text: 18 November 1963
context_en: Push-button telephone
  Western Electric experimented as early as 1941 with methods of using mechanically activated reeds to produce two tones for each of the ten digits and by the late 1940s such technology was field-tested in a No. 5 Crossbar switching system in Pennsylvania. But the technology proved unreliable and it was not until long after the invention of the transistor when push-button technology matured. On 18 November 1963, after approximately three years of customer testing, the Bell System in the United States officially introduced dual-tone multi-frequency (DTMF) technology under its registered Touch-Tone mark. Over the next few decades touch-tone service replaced traditional pulse dialing technology and it eventually became a world-wide standard for telecommunication signaling.
title_en: Push-button telephone