Thank you for all your comments, but my question was not so much about the systems available, but is it possible that the "tones" provided by my computer, when I use a call back system, or my handset when I use a Phonecard and my telephone, can be degraded such that although I may push the 1234 buttons, in fact 1237 is transmitted, therefore connecting me to the wrong number ? Although it is rare, it does happen.
Of course we can all be subject to "finger trouble" but knowing that there is a possibility of mis-slection we are VERY careful when making International calls, yet errors still occur, even to Mrs. ExS yesterday when she tried to call me locally on my cellphone, she didn't have to push the right numbers, just selected it from the memory bank, which she usually does, but that time if called the wrong number. Which supports my theory.
I'm presuming that each digit has a specific tonal frequency, and if ever so slightly off frequency for whatever reason, the wrong digit is transmitted, but maybe not ?
I'm assuming the Tonal Frequency gambit 'cos I recall sometime in the '60's (?) when telephone dialling was moving from the rotary dial system to the push button system that we use now, some Smart Alec in the USA invented what was called the "Blue Box", i.e. he created a gadget that mimicked the sound of the buttons being pressed and used it in public telephone boxes to make free toll calls. I have no idea how he did it, and of course he was eventually apprehended, but his system depended upon creating the right sounds for each of the keys that he might otherwise have pressed on the telephone keypad.
Another thing !! Telephone keypads have a top row of buttons that read 1 2 3, but electronic calculators have a top row that reads 7 8 9 - but as they are both the product of the modern electronic age, couldn't they have got together !! The whole idea of the British 999 number for Police emergencies was because one could find the last hole on the old rotary dial even in the dark, but now, if I have to dial the Police in a situation where I can't see the keypad I would have to remember which key was the 9 ? Is it third from the top of the right hand column, as on a telephone, or top right as on a calculator. KISS. You may think this is inconsequential, but when you are over 80. and can't even remember where the car keys are - you might agree with me !!
Last edited by ExSp33db1rd; 25th Sep 2015 at 00:40.