What is sound?


Simple enough question, a question that for some come feel almost impossible to understand but knowing what sound is can help you understand other aspects about audio


Level 1 (for children):

Sound is a physical sensation that we experience when something vibrates in the world around us. When you talk or make noise, your vocal cords vibrate, creating sound waves that travel through the air and into someone else's ears. Our ears are sensitive to these sound waves and help us understand what the sound is, whether it's someone talking to us, music playing, or even the sound of a bird chirping outside.

Example: A simple experiment you can do with a child to demonstrate sound is to take a metal spoon and tap it on a glass. The sound the glass makes is a result of the vibrations created by the spoon hitting it. The child can feel the vibrations by touching the glass, and they can also hear the sound the glass makes.


Level 2 (for adults):

Sound is a physical phenomenon that involves the transfer of energy from one object to another through a medium, such as air or water. When an object vibrates, it creates a disturbance in the surrounding medium, which propagates as a pressure wave. Sound waves are characterized by their frequency, wavelength, and amplitude, and can be described mathematically using the wave equation. Different sounds have different properties like pitch, loudness, and timbre, which are determined by the characteristics of the sound wave.

Example: A simple experiment you can do to demonstrate sound properties is to make a straw oboe. By cutting a small triangle out of a straw, you can create a reed that will vibrate when you blow into the straw. The vibration of the reed creates a sound wave, which travels through the air and can be heard as a musical note. By covering the hole in the straw with your finger, you can change the pitch of the note, demonstrating the relationship between pitch and frequency.


Level 3 (for scientists at heart):

Sound is a mechanical wave that propagates through a medium by transferring energy from one particle to another. When an object vibrates, it creates a disturbance in the surrounding medium, which causes adjacent particles to vibrate as well. Sound waves can be described mathematically using the wave equation, which relates the frequency (f), wavelength (λ), and amplitude (A) of the wave:

y(x,t) = A*sin(2πf(t-x/λ))

where y is the displacement of the wave at position x and time t, and sin is the sine function. The wavelength λ is the distance between two consecutive points in the wave that are in phase, and the frequency f is the number of complete oscillations of the wave per unit time. The amplitude A is the maximum displacement of the wave from its equilibrium position.

Sound waves can also interact with each other, resulting in phenomena like interference and diffraction, and can be affected by the properties of the medium they are traveling through, such as temperature and pressure.

Example: A simple experiment you can do to demonstrate sound wave properties is to use a speaker and a microphone to observe interference. Set up a speaker playing a steady tone and place a microphone at different locations in the room. By moving the microphone around, you can observe how the sound waves from the speaker interact with each other, creating areas of constructive and destructive interference. This experiment demonstrates the concepts of wave interference and wave propagation in sound, and can be extended to explore more complex phenomena like diffraction and resonance.


I hope my explanation can help you understand this topic a little better and you walk away with a better understanding about the question.. What is Sound?