The echo is there, but it occurs so soon after the direct sound that your
ear/brain system can't perceive the separation between them.
secondary means you were there and saw the info primary mean you have heard it from somewhere else
.The frequency increases
Compression waves happen when particles within a wave are close together rather than spread out. Anything that has a sound is a compression wave that can be heard.
Sound is sensed only when vibrations produced by a source is transferred to the ear drum by means of a material medium. If such a medium is absent then sound cannot be heard. But vibrations of the source are always there.
If a surface is flat, then all the points on that surface will lie in a single "Plane". Any number of lines connecting the points on the surface will all lie within this same Plane. This is basically a Mathematical Definition. I have never heard of a "scientific" meaning before.
Well, I don't know the exact distance - and in fact it would depend a bit on the person. But if the reflecting surface is too close, you would hear the reflected sound wave TOGETHER with the original sound. Actually there would always be a time difference, but if it is too small, we can't perceive it, and will just perceive original sound + echo as a single, albeit louder, sound.
Hang reflecting panels from the ceiling behind the Orchestra.
Technically, the person would hear the sound twice ... once when it passes him on the way toward the smooth surface, and once after it reflects from the surface and passes him again in the opposite direction. In practice, though, you can't detect two seperate sounds if they come too close together in time. So the person standing near the wall could only hear both sounds if he's something like 56 feet or more from it. (0.1 second delay between the incident & reflected sounds)
In the ER, we don't listen until 10 weeks. It can be heard earlier but it is unreliable and only if the fetus floats close to the surface. joymaker rn
Yes, it is a condition in which the anus can no longer fully close, rendering a person incapable of retaining gas. Source: How to Live with a Huge Penis, ISBN: 9781594743061
I heard something very disturbing about Charles, but I won't reveal my source.
The source that Jonas had thought that he had heard behind him might have been just his memories of music, giving him what he was wishing he would hear.
From a reliable source, I heard it was Jeff Foxworthy....
secondary means you were there and saw the info primary mean you have heard it from somewhere else
Yes. I heard Uranus was close by.
I am not sure of this but I've heard from a very reliable source that they do get married... once again I am not 100% sure.
No. Pebble Tec is usually damaged at rolls in the surface such as at a step or on the bond beam. Never heard of chemicals causing cracks.