this is not true.the keypad on phone only have THREE dffreient tones. for the 3 columns.each key on the right most column has the HIGHEST tone. the middle one has middle pitch. the leftmost column has LOWEST tone.this means 1,4,7 and */+ have LOWEST tone2,5,8 and 0 have middle tone3,6,9,# have highest tone.there is no way you could have guessed the exact password just by hearing tones.I know this because I work for a small company that makes land phone sets.