Frequency and Sampling Frequency

Which is the frequency of a tone heard when played with twice the original sampling frequency?

For example, we have this tone:

>> fs=24000; % Sampling frequency
>> t=0:1/fs:1;
>> x=cos(2*pi*1000*t); % frequency = 1000 Hz
>> sound(x, fs);

There we see that the frequency is 1000 Hz, but if we play the tone with twice its sampling frequency:

>> sound(x, 2*fs);

Which is the frequency of the tone then?

Answer 1

[Star Strider]

This is more a philosophical question than a mathematical one.

The frequency of the original signal remains ‘fs’ regardless, The frequency of the generated tone is whatever is passed to the sound function, here either ‘fs’ or ‘2*fs’.

At least that is the way I interpret it.

[Ban Coder]

I get it!! Thanks a lot!!

[Star Strider]

As always, my pleasure!