About speed of sound? Even though Speed of sound at room temperature is very large equal to 342m/s yet it does not cover that much large distance when we speak. What are the conditions at which sound really travel 342m in a single second. 
 A: Unless the sound is directionally focused, it will reduce by the square of then distance. Hence, the level of a sound at 100m distance is only 1/10000 the intensity of the same sound 1m away. Because of this, as the source gets further away, the intensity of the sound rapidly reduces. Nearby noise, however, still stays loud, making it harder to distinguish the sound you are listening for.
Therefore, to hear a sound 300m away, it needs to be quite loud, or you need to be in a very quiet area. A hammer hitting a nail may be just audible, a rifle shot will be very clear, but a speaking voice will disappear in the noise.
In all cases though, the sound will travel at the same speed.
A: Anytime anything loud enough to be heard from 342 meters away makes a noise. For instance if you hear an airplane going by overhead, the sound from it has traveled many hundreds of meters in a handful of seconds.
A: You need to distinguish between the speed of sound and the intensity of sound. In general, the two are not closely related although as intensity increases all kinds of non linear effects can alter the speed of propagation of the sound. The most obvious being a supersonic shock wave from explosives detonating.
A: I think what you really want to ask is:

How can I make an experiment that involves hearing the sound with a delay of 1 second?

I remember the most convincing case for me was looking at some noisy road-works from a large distance (a few hundreds of meters). A worker was pounding a metal spike into the ground with a hammer. I heard the sound with a delay.
You can arrange something like this yourself. For that, you need a sufficiently quiet environment (e.g. outside the city) and a sufficiently loud noise (e.g. pounding a hammer on a metal rail). You need the noise to be sharp (not continuous), and you need a clear visual signal that tells you when it happens - so e.g. a passing train, while loud enough to hear from a long distance, is not convincing.
A suitable natural sound source is thunder, which is caused by lightning, but its distance is blurred, because the lightning is very long. Also, you cannot arrange it artificially, which is not good for an experiment.
