Console.Beep in action

I can hear it, too, subjectively, painfully high pitch. (Hurray! I'm young again!) But I also can here low-frequency clicks. Nothing wrong is perceived for audible frequencies; and the musical tones sound realistic (if they are not too low, where discretization errors are considerable). But the tone is pretty dirty.

This does not yet proof anything. But then I lowered your tone by some hundreds of hertz, and… subjective tone of high pitch did not change. It's already wrong. Moreover, when I lowed the tone by 2/3, 3/4 and 1/2 (perfect fifth, perfect fourth and octave, the intervals most distinctly perceived and detected by human year as most harmonic, due to obvious physical characteristics of human hearing), the audible tone… completely disappeared despite the fact that it should become closer to the normal human-audible domain.

Probably, you should not take this generation too seriously.

But the question is very good, I appreciate it.

—SA

There are 2 propositions one can consider:

a) You CAN hear way above 20kHz
b) The speaker is NOT vibrating at 32kHz

To test proposition a your equipment is totally inadequate. Why do auditory labs have the equipment and facilities they have? So lets rule that out for the moment.

Proposition b seems most likely. The audio amplifier may supply a 32kHz voltage but even in the world of esoteric hifi a tweeter capable of vibrating at 32kHz is very rare. The speaker is vibrating at some other frequency in response to the input and my guess would be it's resonant frequency - probably a few kHz.

This test is illuminating:

for (int freq = 100; freq < 32767; freq += 300)
{
    Console.WriteLine(freq);
    Console.Beep(freq, 200);
}

The perceived increase in frequency stops long before the upper limit. This is where the audio system stops being capable of following the input.

If we consider this example:
https://msdn.microsoft.com/en-us/library/4fe3hdb1(v=vs.110).aspx[^]

and add:

// Define the octave multiplier.
protected enum Octave
{
    same = 1,
    one = 2,
    two = 4,
    three = 8,
    four = 16,
    five = 32,
    six = 64,
}

and:

// Play the notes in a song.
protected static void Play(Note[] tune, Octave octave = Octave.same)
{
    foreach (Note n in tune)
    {
        if (n.NoteTone == Tone.REST)
            Thread.Sleep((int)n.NoteDuration);
        else
            Console.Beep((int)n.NoteTone * (int)octave, (int)n.NoteDuration);
    }
}

then we can do:

// Play the song
Play(Mary, Octave.two);

By octave 5 the notes are starting to sound the same which means we are reaching the limit of the system to faithfully reproduce the input.