Question

Acoustics and Resonance:

What is pitch? How does it relate to the properties of a wave? How is the pitch of a note changed?

Answer 1

Sir,

Answer is given below.

We can say simply pitch is the rise and fall of our voice when we speak, sometimes called highness or lowness. Pitch is also defined as the quality of a sound governed by the rate of vibrations producing it.Pitch is also determined by the frequency of sound wave vibrations.So pitch is related with sound wave.

Actually the sound is a wave,so we relate the properties of sound to the properties of a wave. From the basic properties of sound,pitch is very important one.We know that pitch is determined by frequency,so frequency of sound wave is what your ear understands as pitch.A higher frequency sound has a higher pitch,and alower frequency sound has alower pitch.We can only hear the sound of frequency range from 20 to 20,000Hz.

We know that sound is caused by the molecules of a medium vibrating.Because when we consider the sound waves traveling through air or any medium affect the objects that they encounter.Actually frequency is the number of vibrations that an individual particle makes in a specific period of time(second).

Pitches are not same as notes. A note can be tuned to a different pitch.This means that it can be adjusted slightly higher or lower.To understand how the pitch of a note changed,we consider the string.We know that string vibrates with a particular fundamentaal frequency.However,it is possible to produce pitches with different frequencies from the same string.Here the frequency of string depends on properties like

1. Length of the string :When the length of the string changed,it will vibrate with a different frequency.Shorter strings have higher frequency and also high pitch.When a musician presses her finger on a string,she shortens its length.The more fingers she adds to the string,the shorter she makes it,and higher the pitch will be.
2. Diameter of the string :Diameter is the thickness of the string.Thick strings with large diamteres vibrate slower and have low frequencies than thin ones.
3. Tension of the string: A string stretched between two points,such as on a stringed instrument will have tension.Tension refers how tightly the string is stretched.Tightening the string gives it a higher frequency while loosening it lowers the frequency.
4. Density of the string: It also affect the frequency.The more dense the string is,the slower it will vibrate,and the lower its frequency will be.

On changing these properties we can changed the pitch of a note.

Thank you