So what type of wave is sound? Sound waves fall into three categories: longitudinal waves, mechanical waves, and pressure waves. Keep reading to find out what qualifies them as such.

As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source.

The matter that supports the sound is called the medium. Sound cannot travel through a vacuum.

Sound waves are mechanical waves, so they can travel only though matter and not through empty space.

To create a sound, we have to set matter – whether it’s a gas like air, a liquid or even a solid material – in regular motion, creating a wave of specific frequencies, which we hear as a sound of a particular pitch. Eventually the motion ceases entirely and no more sound can be heard – producing silence.

Explainer: What is Acoustics? These vibrations, or sound waves, carry a tiny amount of force. Although the force of sound is weak, it can move small objects when used in just the right way.

The displacement from an equilibrium position of mass (atoms in a material) is perceived as sound. Both quanta are believed to be massless, but up to very recently — and almost by accident — it was found that phonons do in fact carry a very small amount of mass. They are massive.

In this way, waves can have no mass but still carry momentum. In addition to being a particle, light is also a wave. This allows it to carry momentum, and therefore energy, without having mass.

Sound waves are pressure waves and depend on density so gravity which stratifies the atmospheric density affects sound waves through that. In solids and liquids to the extent that gravity stratifies them it will change the behaviour of sound waves.

We can hear gravitational waves, in the same sense that sound waves travel through water, or seismic waves move through the earth. The difference is that sound waves vibrate through a medium, like water or soil. For gravitational waves, spacetime is the medium. It just takes the right instrument to hear them.

Light and sound are not regarded as forms of matter. In contrast, matter is made up of particles that do have mass. Sound is a little different in that it is the propagation of a pressure wave through a medium of particles. Since it is a wave, it is not considered a form of matter.

The gravitational field is really a curving of space and time. The stronger the gravity, the more spacetime curves, and the slower time itself proceeds. Gravitational time dilation occurs whenever there is difference in the strength of gravity, no matter how small that difference is.