On Mon, 26 Nov 2007, Sergei Steshenko wrote:
On Mon, 26 Nov 2007 10:52:17 -0800 (PST)
Bill Unruh <unruh@xxxxxxxxxxxxxx> wrote:
On Mon, 26 Nov 2007, Sergei Steshenko wrote:
On Mon, 26 Nov 2007 18:19:24 +0100
Benoit Rouits <brouits@xxxxxxx> wrote:
Le dimanche 25 novembre 2007 à 18:26 +0300, Vladimir Mosgalin a écrit :
That's the main reason why I asked - I heard that people can hear
22khz or about that when they are young, than listening gets worse and
they don't hear very high frequencies anymore - and since I consider
myself still young ;), I was kind of disappointed by the fact that I
can't hear not only 22khz, but even 20khz, and when I discovered that
I can't hear even 18khz, I was kind if scared - is my hearing going
down due to headphone usage? Thanks for clarifying this issue.
Theorically, A 44100 sampled audio CD can reproduce a triangle signal
at 22050 Hz.
No, it can't.
Sure it can. The difference between a triangle wave and a square wave a
22000 is harmonics whose frequency is far higher than 22050. Ie, the
harmonics are irrelevant. Thus a triangle, a square, a sine, a sawtooth are
all the same. One could say that the triangle is closer since it has lower
amplitude harmonics than most of the others.
Draw timing diagrams with different relative phases of the signal and
sampling frequencies.
Your output will be 22050 Hz 50% duty cycle square wave whose amplitude
(and polarity/phase) depend on the above relative phase.
I'm saying it again - just draw the suggested timing diagram.
It will be a very good illustration of aliasing.
Furthermore, if the phase is such that sampling occurs at every
zero crossing, the sampled signal will be 0/zero/null/zilch - you name
it.
The point/problem that the original poster suggested input signals with
fundamental being the exact Nyquist frequency.
Sure, but I did not think that was his point, or yours. Ie, the amplitude
may depend on the relative phase, but the question was triangle or square
wave I thought.
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