Hearing sounds is considered to be one of the senses that living beings have got as a gift. Sound waves can never die, they only travel from one medium to another. There are a lot of interesting facts about sound which we will be learning as we go further. However, there are also a few basic things that we need to understand when it comes to sound.

## What Are Waves?

Waves are created when there are disturbances in the particles that carry energy from one medium to another. These waves are transverse and longitudinal waves. These are the two types of waves.

When the particles in the medium vibrate back and forth, then the wave is known as a longitudinal wave. Solids, liquids, and gases act as a medium for the propagation of longitudinal waves. Sound waves are an example of longitudinal waves.

When the particles in the medium vibrate up and down, then the wave is known as a transverse wave. Solids and liquids act as a medium for the propagation of transverse waves. Transverse waves cannot propagate through gases.

## What is a Sound Wave?

A sound wave is defined as the wave that consists of alternating compression and rarefaction. When the wave is compressed, it is in the high-pressure region and when the wave is expanded, it is in the low-pressure region. The speed at which these wave particles travel or propagate is constant.

### Characteristics Of Sound Waves

To describe a sound wave, there are five characteristics, and they are wavelength, time-period, frequency, amplitude, and the velocity of the speed of sound wave.

• Wavelength: The minimum distance at which a sound wave repeats is known as the wavelength. The wavelength is denoted by λ and the SI unit is metre. Also, the distance between the centers of the compression and the rarefaction is always equal to half of the wavelength.
• Time-period: Time taken by the wave to complete one cycle is defined as the time period of the sound wave. When one full vibration is produced by the body, it is known to complete one cycle. Letter T is used for denoting the time period and the SI unit is seconds.
• Frequency: Frequency is defined as the number of complete cycles produced in one second. The SI unit of frequency is hertz. One hertz is equal to one vibration per second. Letter f is used for denoting frequency. Also, the relationship between frequency and time period is that f = 1/T.
• Amplitude: Amplitude of a wave is defined as the maximum displacement of the particles in the medium from their actual position. The SI unit of amplitude is metre.
• Velocity: The velocity of the wave is defined as the distance traveled by the sound wave in one second. The SI unit of the velocity of the sound wave is meter per second. The relationship between velocity, frequency, and wavelength of the sound wave is that the velocity of the sound is the product of frequency and the wavelength.

## Facts Related To Sound

• Sound waves can travel through different mediums such as solids, liquids, and gases. The velocity of sound is 4.3 times faster in water than in air.
• Flies produce the buzz but the interesting fact is that flies cannot hear any sound.
• The study of sound waves is known as acoustics.
• Melophobia is known as the fear of music.
• Animals use sound waves to detect obstacles.