I just wondered this randomly after I called to order pizza. You know how each number, when pressed, on the phone has a different tone to it?
Is there a specific reason for that?
2007-04-01 12:01:36 · 12 answers · asked by donmartin46 1 in Consumer Electronics ➔ Land Phones
Those tones are referred to as DTMF or Dual Tone Multiple Frequency. You can go to (www.dialabc.com/sound/dtmf.html) to get the actual tones. Years ago, and as late as the 70's most phones used what was called pulse dialing. Pulsed was a series of on and off's. a one was on-off-on, a two was on-off-on-off-on and so on all the way through ZERO. It was simple, but very slow. The DTMF tones were developed to speed up the calling cycle and to simplify the telephone switch design. Today the DTMF tones are still used from the telephone, but the office and all of the long distance use digital technology.
Hope that helps.
2007-04-01 13:22:04 · answer #1 · answered by ttpawpaw 7 · 2⤊ 1⤋
Phone Number Tones
2016-11-04 05:30:32 · answer #2 · answered by branaugh 4 · 0⤊ 0⤋
Yes, there is a very good reason. Those DTMF signals are how the phone system "knows" what buttons you push. There is a row tone and a column tone, and what you here are both tones beating together.
In the older, pulse phones, the dial would open and close the contacts as a way of telling the network what number you dialed. If you dialed 9, the contacts would open and close 9 times.
On the touch tone phones, I'm sure that a pair of guys have tried whistling the phone number. It would take 2 people since there are 2 bands of tones. One would have to take the high portion of the tones, and the other would have to take the lower portion. I've never been able to use my voice to trick a phone into dialing, but I have attempted to handshake with a modem before. I'd call up a BBS and in the tenor range, I'd go, duhhh, duh (maybe E4 and F4), and sometimes the tones on the other end would alter, "thinking" I was a modem.
2007-04-01 15:45:27 · answer #3 · answered by Anonymous · 1⤊ 0⤋
numbers phone tones pressed
2016-02-01 10:38:32 · answer #4 · answered by ? 4 · 0⤊ 0⤋
How else is the phone going to know what number you're calling? The different tones get sent to the switchboard, the switchboard sends the call to the area, the exchange, and then to the phone with the number. Each tone has a "meaning" in numbers.
2007-04-01 12:13:58 · answer #5 · answered by sonyack 6 · 1⤊ 2⤋
the DMTF tones that you hear when you press diffrent numbers or the * and # keys are used by the switch to determine what numbers that you pressed so that your call can be placed. If you recorded those tones, and played them back into the speaker of the telephone (as long as there was no distortion or noise in the recording) you would be able to dial the number that you recorded..
2007-04-01 12:12:59 · answer #6 · answered by joe r 7 · 2⤊ 1⤋
Ever think it could be for blind people? They cant see but they have a high sense of sound and maybe they memorize the beeps to know what they are pressing. Just a thought!
2007-04-01 12:07:49 · answer #7 · answered by Anonymous · 2⤊ 2⤋
If someone is blind they listed to the tone or set it to numbers and it beeps the number.
2007-04-01 12:09:53 · answer #8 · answered by Anonymous · 1⤊ 2⤋
Good question, I was wondering about that too. I think it is for blind people to determined if they got the right button? I could be wrong.
2007-04-01 12:11:12 · answer #9 · answered by Anonymous · 0⤊ 2⤋
THATS TO LET A BLIND PERSON KNOW WHICH BUTTON THEY ARE PUSHING IF THAT HAD TO USE A RAGLER PHONE AND NOT A BARL PHONE I THINK
2007-04-01 21:45:14 · answer #10 · answered by m_moore212000@sbcglobal.net 2 · 1⤊ 1⤋