Sound Replication - Part 2?

Question

The phone digit 1 is a combination of 2 frequencies.
1209hz + 697hz

Now, if you had 2 seperate speaker that played each frequency, would you hear the combination of the 2 frequencies, or would you be able to make a distinction?

I gues the answer would depend on the speakers placement proportional to your ears.
If they were at the exact same distance, it would appear as the combination. If there was any deviance to the placement of the speakers, then you would be able to differentiate the signals.

I believe that to be true. I just wish I had the equipment.

You know, come to think of it, There is a seperate Left and Right Channel. I will be able to perform the test.

School for Audiology and you still don't know that you can't produce 2 frequencies from 1 speaker at the same time?

You can't do it!
What you are hearing is the addition of the 2 frequencies. Not the 2 frequencies.

I jumped the gun. I am probably wrong.
It is just weird. I am confusing myself.
Working too long.

I think what I am not seeing is the signal processing, where you can subtract each Frequency from the combination of Frequencies, resulting in the 2 different frequencies.

Sort of like the way a Spectrum Analyzer works with FFTs.

To me, it appears as the result of adding the 2 frequencies, resulting in a 3rd frequency. That is why it is so confusing.
1209 and 697 != 1906, but some strange combination of the 2 frequencies.

I don't know yet, how you can add 2 frequencies and not come up with a third one. That is what is baffling me.

I wonder if there are introduced harmonics, which are separated?

It is strange how that works.

Oh well.

Answer 1

If each tone is coming from a different speaker, and if you have normal hearing across all frequencies in both ears, you will be able to distinguish each tone. Since the source of each sound would be coming from a different location, a normally functioning central auditory nervous system will utilize the subtle differences caused by the location variance to perceive the tones distinctly. The further apart the speakers, the more distinct the tones.

But we can differentiate even when the tones come from the same speaker - the push-button telephone sounds are all two distinct tones based on which row and column they are on the keypad. I was able to figure this out LONG before I went to school for Audiology. Separating the sound source of each tone will only make the distinction easier.