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?