<P> Although push - button touch - tone telephones made their debut to the general public in 1963, the rotary dial telephone still was common for many years . In the 1970s the majority of telephone subscribers still had rotary phones, which in the Bell System of that era were leased from telephone companies instead of being owned outright . Adoption of the push - button phone was steady, but it took a long time for them to appear in some areas . At first it was primarily businesses that adopted push - button phones . By 1979, the touch - tone phone was gaining popularity, but it wasn't until the 1980s that the majority of customers owned push - button telephones in their homes; by the 1990s, it was the overwhelming majority . </P> <P> Some exchanges no longer support pulse - dialing or charge their few remaining pulse - dial users the higher tone - dial monthly rate as rotary telephones become increasingly rare . Dial telephones are not compatible with some modern telephone features, including interactive voice response systems, though enthusiasts may adapt pulse - dialing telephones using a pulse - to - tone converter . </P> <P> The international standard for telephone signaling utilizes dual - tone multi-frequency (DTMF) signaling, more commonly known as touch - tone dialing . It replaced the older and slower pulse dial system . The push - button format is also used for all cell phones, but with out - of - band signaling of the dialed number . </P> <P> The touch - tone system uses audible tones for each of the digits zero through nine . Later this was expanded by two keys labeled with an asterisk (*) and the pound or hash sign (#) to represent the 11th and 12th DTMF signals . These signals accommodate various additional services and customer - controlled calling features . </P>

Is a mobile phone a touch tone phone