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Assuming a normal earth/air listening environment with a normal speaker and a human listener...

Sound travels in a room when air particle A (near a speaker) collides with air particle B, etc, until air particles near a human's eardrum are collided with to cause the eardrum to vibrate.

A higher frequency tone (1000Hz) would cause particle A to move away from the speaker at a higher velocity than a lower frequency tone (100Hz), which seems to indicate that the 1KHz tone will reach the listener slightly before the 100Hz tone. I'm thinking this because the particles disturbed near the listener will be disturbed sooner by the 1KHz tone. Is this correct, or am I missing something?

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I think that you are forgeting that a higher frequency would also make the particles go back faster, with the movement of the speaker's membrane. Sound is a wave, and is the wave propagation velocity the one you are going to measure.

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  • $\begingroup$ Are you telling that sound propagation depends on the frequency? $\endgroup$ – user130529 Oct 28 '16 at 20:15
  • $\begingroup$ @claudechuber it depends, indeed, because of the properties of the medium. I'm just proposing a counterexmple to Danaiel Smith's reasoning, to demonstrate that in a first order of aproximation the frequency does not matter, and to explain that he is thinking in sound more like one would think of a particle instead of like a wave. $\endgroup$ – RedPointyJackson Oct 29 '16 at 9:53
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    $\begingroup$ In the basic (second order) wave equation, the sound speed does not depend on the frequency, which is the usual way of treating waves propagating in air, and seems to be the assumption made here ("normal earth/air listening environment"). Though I agree that this is only an approximation, and introducing higher order terms can bring dispersion. $\endgroup$ – user130529 Oct 29 '16 at 12:45
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The speed of both frequency sounds once they leave the source is same.

But going into too much details - Think about a single pulse of two frequencies. It takes longer to generate the lower frequency pulse as compared to higher frequency pulse. So, the lower frequency pulse last that much longer at the destination. Not because it was moving slower through air, but because it was being generated slower. The longer lasting pulse can give impression of a slower moving pulse.

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