12. Images Used:
(In Chronological Order)
7-25-16_kniwingPark_Flickr_ear
7-25-16_ReflectedSerendipity_Flickr_Ripple
7-25-16_Dan Century_Flickr_The inside of your ear
7-25-16_HarmonicPartialsonstring_Wikimedia_Qef
Notas do Editor
Intro:
Hello, my name is John Hammond
My presentation is on, as you can see, Pitch and Fundamental Frequency
We will begin with pitch.
What this title means, is the effect that a frequency has on the brain, and ear
Directly proportional – No frequency, no pitch
Low frequency, low pitch
High frequency, high pitch
Some people, especially musicians, have the ability to hear even a difference between 2 Hz (Hertz, the measure of frequency)
Now... Not only are you probably asking the question of how these people can hear such a miniscule difference, but how can anyone hear sound?
To begin with, think of sound like a ripple in a pond. Sound creates vibrations through objects, and those vibrations create more vibrations, etc., until it reaches your ear.
Once the sound waves get to your outer ear, it vibrates your eardrum. That then vibrates these three bones in the middle ear. Those, in turn, move fluid around in the inner ear. There are thousands of sensitive hair-like cells that then turn that movement into nerve impulses, which are then transferred to the brain. Remember, throughout all these steps, the wavelengths are moving at the speed of sound, which is approximately 761 mph, or 13x the speed of a car on the highway (60mph)
Once the sound waves get to your outer ear, it vibrates your eardrum. That then vibrates these three bones in the middle ear. Those, in turn, move fluid around in the inner ear. There are thousands of sensitive hair-like cells that then turn that movement into nerve impulses, which are then transferred to the brain. Remember, throughout all these steps, the wavelengths are moving at the speed of sound, which is approximately 761 mph, or 13x the speed of a car on the highway (60mph)
Once the sound waves get to your outer ear, it vibrates your eardrum. That then vibrates these three bones in the middle ear. Those, in turn, move fluid around in the inner ear. There are thousands of sensitive hair-like cells that then turn that movement into nerve impulses, which are then transferred to the brain. Remember, throughout all these steps, the wavelengths are moving at the speed of sound, which is approximately 761 mph, or 13x the speed of a car on the highway (60mph)
Once the sound waves get to your outer ear, it vibrates your eardrum. That then vibrates these three bones in the middle ear. Those, in turn, move fluid around in the inner ear. There are thousands of sensitive hair-like cells that then turn that movement into nerve impulses, which are then transferred to the brain. Remember, throughout all these steps, the wavelengths are moving at the speed of sound, which is approximately 761 mph, or 13x the speed of a car on the highway (60mph)
The Fundamental Frequency is also called the First Harmonic. This is the lowest frequency that a specific instrument can play. Think of a guitar string. At this end, the guitar is fixed to the board. At this end, it is also tied off. Therefore, these are Nodes, or places with no displacement when the string is plucked. The Anti-Node is where there is the most amount of displacement, or movement. The definition of the first harmonic, is there is One Anti-Node, between two Nodes, as shown above.
Note that this isn’t a complete wave.
A complete wave must rise up, reach a maximum, go back through the x axis, and up again.
The Fundamental Frequency is cut in half, when it gets to the x axis.
Notice how the first harmonic has ½ of a wave
Second harmonic has 1 wave
Third harmonic has 1 ½ waves
Fourth has 2 waves.
The pattern is, for the n harmonic, there are n/2 waves.