What is the difference between sound and noise?
139029
Traditionally in English, noise is an unwanted sound (slighly bad or neutral).\n\nIn dealing with audio, noise is random hissing, like the sound of a TV with no arial (the visual of this is also called noise). When talking about signal to noise ratio, a high ratio means the desired sounds are much louder than the random noise (can be caused by interference).
924840
sound is the vibration of the air and it's relationship to the ear drum.....no air.......no sound
90438
A radio wave is electromagnetic radiation.\n\nA sound wave is variations in the density of the air that it is traveling through.
220668
Actually, sound travels FASTER in cooler air.\n\nThe speed of sound in a medium (air, water, etc.) is faster when the medium is denser.  Water is denser than air, and sound travels faster in water than in air.\n\nCold air is denser than hot air, so the sound is transmitted faster.  Since the density difference is small, so is the speed difference.  Sound is faster in colder air, but not MUCH faster.
362504
Sound is a waveform passing through a medium (in this case air). Cooler night air is denser than warm daytime air and therefore easier to travel through and propagate. Other factors already mentioned contribute to it seeming louder, but do not help it to travel further.
290448
According to the Merriam-Webster dictionary sound is defined as, "1 a : a particular auditory impression : TONE b : the sensation perceived by the sense of hearing c : mechanical radiant energy that is transmitted by longitudinal pressure waves in a material medium (as air) and is the objective cause of hearing." According to this definition the sound MUST be perceived, therefore, if no one is around, the tree DOES NOT make a sound.
512696
My guess is you are talking about being able to see the flashing lights of a plane at night but cant hear it. Or seeing a high plane with contrails during the day but cant hear that either. Light travels 186,282 mps while sound is only 1100 feet per second. So you see something your mind knows is making noise, but cant hear it because of the distance. Now if the sound has not dispersed through the air by the time it gets to you, then you hear it, but since you cant see what is making it, you dont realize it.
593379
what is the difference between the two
306289
It still sends sound waves through the air, yes.  It does not, however, make noise.  Because noise is defined as something we hear, and obviously no one can hear it.  I know, I have a lot of time on my hands to come up with answers.
269469
Sound travels in waves like light or heat does, but unlike them, sound travels by making molecules vibrate. So, in order for sound to travel, there has to be something with molecules for it to travel through. On Earth, sound travels to your ears by vibrating air molecules. In deep space, the large empty areas between stars and planets, there are no molecules to vibrate. There is no sound there.
653058
Noise pollution is the excess noise produced by cars, buildings, etc. It can disorient animals and prematurely damage hearing. \nMore info on sites below....
788355
White noise is normal sound made of waves of compression travelling through air, so if you are in total silence then you aren't hearing any noise, including white noise.  You might think that in absence of any external stimulation (any noise around you) you would experience hearing nothing yet with nothing around you still do.  The auditory cortex (part of your brain responsible for processing sound information) shows activity under fMRI inspection without any signal coming from the ear.\n\nAnother reason you might hear sound when nothing else is around is that your body makes noise (muscles, heart, blood-flow, organ function).  Try contracting your jaw tightly while in a quiet place,you can hear your own muscles working.\n\nExperience of sound without external stimulation can also be a result of tinnitus. This is caused by damage to the hairs in the ear which sense vibrations in the air (the sound) or to the nerves which carry sound signals to the brain, or even possibly by "central crosstalk" within the brain.
1072685
Noise is created with the movement of particles.  The popping noise is caused by the air particles inside the balloon very rapidly moving outside the balloon.
248338
sound is created when somthing makes a vibration in the air the vibrations move through the air like waves. to understand more clearly drop a rock in water and watch the waves from the rock that will give you a good idea of how sound travels
148
In a sense, any microphone is picking up sounds from the past, due to the speed of sound. This is similar to what you mentioned with radio telescopes.\n\nThe main differences are 1) velocity -- light moves at about 1 foot per nanosecond while sound moves around 1 foot per 1/1000 second, and 2) that sound moving though a medium diffuses quite rapidly. Something really loud, like thunder, you might hear from 20-30 seconds away. For normal, everyday sounds, the delay won't be more than maybe a few tenths of a second.
997346
See this all depends.... if this were in the philosophy section, then it could be debatable.  But alas- it's in the botany section, so yes- it does make a sound.  Friction is created as it falls through the air and hits the ground, and that friction causes soundwaves.  Whether someone is there or not is irrelevant.  Humans can only pick up on a certain range of decibels anyways.  That doesn't mean just because we can't hear it, it doens't make a sound.  It just means that we can't hear it.  People need to get unstuck from themselves and think outside the human box.  "If humans can't.... must not be possible."  Meh.
279774
Light and sound both travel through waves, though light travels fatser than sound. Light does not require any medium for transport, so it is called an electromagnetic wave. Sound however needs a medium as it is transmitted through the vibrations of the particles of the medium. It is called a mechanical wave.