Phone beep?

Question

You know how whenever you type someone's number in, you hear a single beep varying in pitch for each number you press? Is it possible to dial a number just based on the sounds of each number?

Answer 1

very interesting ?. I don't think that is possible unless you've memorized the sound of the beeps on your phone for each number. Otherwise, I don't think so.

Answer 2

Each digit you press actually sends a combination of two different tones, a lower-pitched tone which represents the row the button is in, and a higher-pitched tone which represents the column.  For example, when you press 1 it sends a tone of 697Hz plus a tone of 1209Hz.  Press 2 and it sends 697 plus 1336, 8 is 852 plus 1336, and so on.

The equipment at the telephone office recognizes these pairs of tones and translates them into the appropriate digits.

So yes, if you use anything which can generate the correct pairs of tones and send them down the line, you can dial a number.   You'll never be able to whistle them, since you need the two tones simultaneously, each at exactly the right pitch.  That's why the system was designed to work with two tones per digit, so that background noises and normal voices would not be mistaken for numbers being dialed.