no one can focus on the superficial quite like marketing.

I'm still reeling from how gut-punchingly hard I agree with this.

About all I really get via the Postal Service would qualify as spam if it hit my email inbox. And gets treated that way when it hits my mailbox.

You eat your junk mail?!

:-/

I had the opposite problem. In Germany and Austria, I'd try to speak German and as soon as they heard my American accent they would speak English back to me.

> If you take three electronically produced 15kHz tones, one a sine wave, one a sawtooth wave, and one a square wave, that teenager can tell the difference between them.

That statement doesn't fit into my understanding how sound works and how humans hear. I'd be very interested to see a double-blind test where this is demonstrated, and not due to an error in the sampling process.

The thing that makes a tone a sine, sawtooth, or square wave is the presence or absence of harmonics. The first harmonic above the fundamental on a 15kHz tone would be 30kHz - inaudible. All any human (even with hearing up to 25kHz) can hear with any of these three tones is the 15kHz fundamental: a sine wave.

The parts of the shape you lose by sampling at 44.1kHz are the parts that make up the harmonics: 30kHz, 45kHz, 60kHz, 75kHz, etc. Since no human will ever hear those frequencies, they are OK to discard in order to sample at 44.1kHz. There will be a difference to the wave shape, but it will be *completely* inaudible to any human being. (Bats would notice it, though.)

All any person would ever hear in any of those three waves is a 15kHz sine, so all you need to record in this case is that frequency (unless you're planning to slow down/pitch shift the recording by several octaves, or play it for bats, or something).