Sound Waves and Hearing

Sound is produced when an object vibrates and can only travel through a medium, such as a solid, liquid or gas.

Sound waves are longitudinal, which means the vibrations occur parallel to the direction of wave travel. As a result, sound waves exhibit periods of compression and rarefaction.

Sound Speed

Sound travels at different speeds, depending on the medium. Even though sound travels very fast, it is still possible to measure the speed of sound over a given distance, which is measured in metres per second (m/s).

  • The speed of sound in air is 343 m/s
  • Sound travels almost 5 times faster in liquids than in air – For example, the speed of sound in water is 1,481 m/s
  • The speed of sound in solids is around 6000 m/s – Sound travels the fastest in solids

Sound waves travel faster in media where particles are closer together. As you can see in the list above, sound travels fastest in solids, then liquids and then slowest in gases. This is because the particles of solids are closest together, then liquids and then furthest apart in gases.

When sound travels in a solid, the particles are very close together. Therefore, when particles in solids collide, they transfer energy faster than in liquids or gases.

The speed of sound waves also depends on the density of an object. The more dense an object is, the faster sound will travel through it.

Sound in Space

Sound waves travel through the vibration of particles in a medium, whether it be air, water or solid materials. In many everyday contexts, we experience sound as vibrating air.

Since space is a vacuum with no particles to vibrate, sound cannot travel through it.

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