Why Do Guitars, Violins And Tuning Forks All Sound Different.?
Say I play a note on a Guitar, a violin & then hit the same ntoe on a tuning fork. Just for ease, say A at 440 hertz. Why do they all have a different sound. Or for that matter, why do two guitars have a different sound. If its all 440 hertz sine wave coming off, shouldnt it all sound the same?
Kind of like how all 630 nanometer light is red, & it doesnt matter if its a laser, LED LCD or black body type emitter?
January 30th, 2010 at 5:43 pm
‘CAUSE THEIR FREQUENCY IS DIFFERENT
January 30th, 2010 at 6:57 pm
FREQUENCY IS DIFFERENT
material IS DIFFERENT
form IS DIFFERENT
January 30th, 2010 at 11:14 pm
I don’t know exactly,but the sound doesn’t seem to have frequency & wave longitude as the only characteristic,but also its “color”,which depends on its origin-which instrument is playing it.
January 31st, 2010 at 5:36 am
First of all, their freq. is NOT different…you specified one freq. for them all. What is different is their harmonics. Here’s what Wiki has to say:
“In acoustics & telecommunication, the harmonic of a wave is a component frequency of the signal that is an integer multiple of the fundamental frequency. For a sine wave, it is an integer multiple of the frequency of the wave. For example, if the frequency is f, the harmonics have frequency 2f, 3f, 4f, etc.
In musical terms, harmonics are component pitches of a harmonic tone which sound at whole number multiples above, or “within”, the named note being played on a musical instrument. Non-integer multiples are called partials or inharmonic overtones. It is the amplitude & placement of harmonics & partials which give different instruments different timbre (despite not usually being detected separately by the untrained human ear), & the separate trajectories of the overtones of two instruments playing in unison is what allows one to perceive them as separate. Bells have more clearly perceptible partials than most instruments.” [See source.]
Thus, your 440 Hz A is the fundamental freq. you pluck, blow, stroke, bang, etc. on whatever instrument you might be using. The overtones of that fundamental A are what allow you to distinguish the different tonalities of each instrument.
It turns out about anything that vibrates has harmonics. That includes both sound & light, even though the nature of the waves is quite different. Rigorous understanding of harmonics requires skill in complex mathematics (like partial differential equations & complex algebra).
January 31st, 2010 at 8:49 am
Best way to look at it is with an oscilloscope…
The basic (by which I mean the strongest) frequency of the note that you are playing on any of the in-tune instruments is the same (ie your 440 Hz). If it is run through frequency analysis (electronic tuner) it will show you that they are all the same.
However, there are many other frequencies that make up the sound of the particular instrument. This is what makes it sound different.
There are some good resources where you can see the sound pattern:http://www.mindspring.com/~scottr/zmusic…http://www.glenbrook.k12.il.us/gbssci/ph…
January 31st, 2010 at 9:21 am
It’s due to overtones. The tones produced by musical instruments are not pure tones – they would sound pretty boring if that were the case.
A guitar string may be vibrating at 440 Hz, but it will also be producing other frequencies, mostly harmonics of the fundamental (440). Also, if you put the sound into an oscilloscope, you would see that the waveform is not a perfect sine wave. Besides the overtones, you will see that the shape of the wave is skewed one way or another.
Tone generators & tuning forks produce pure tones & their sound will look like a pretty much perfect sine wave on the oscilloscope.
Comparing sound to light, consider that you seldom see pure colors. Most things have colors that are mixtures of many wavelengths; only lasers produce pure colors. The analogy is not perfect, because both the production & sensing mechanisms are different – nobody has “perfect pitch” when it comes to color.