Sound wave

A sound wave is a type of mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.

Properties of Sound Waves

Sound waves are characterized by several key properties:

Frequency

The frequency of a sound wave is the number of oscillations or cycles that occur in one second. It is measured in hertz (Hz). The frequency determines the pitch of the sound; higher frequencies correspond to higher pitches.

Wavelength

The wavelength is the distance between successive crests (or compressions) of a wave. It is inversely proportional to frequency, meaning that higher frequency sounds have shorter wavelengths.

Amplitude

The amplitude of a sound wave is the height of the wave and is related to the loudness of the sound. Greater amplitude corresponds to louder sounds.

Speed

The speed of sound varies depending on the medium through which it travels. In dry air at 20°C, the speed of sound is approximately 343 meters per second (m/s). Sound travels faster in liquids and even faster in solids.

Phase

The phase of a sound wave refers to the position of a point in time on a waveform cycle. It is measured in degrees or radians.

Transmission of Sound

Sound waves require a medium to travel through, such as air, water, or solid materials. They cannot travel through a vacuum. The transmission of sound involves the transfer of energy from one particle to another in the medium.

Reflection

Sound waves can reflect off surfaces, leading to echoes. The angle of incidence equals the angle of reflection.

Refraction

Refraction occurs when sound waves pass from one medium to another, changing speed and direction.

Diffraction

Diffraction is the bending of sound waves around obstacles and openings. It is more pronounced with longer wavelengths.

Absorption

Absorption occurs when sound energy is absorbed by the medium or surface, converting it into other forms of energy, usually heat.

Applications of Sound Waves

Sound waves have numerous applications in various fields:

Medicine

In medicine, sound waves are used in ultrasound imaging to create images of the inside of the body.

Engineering

In engineering, sound waves are used in sonar systems to detect objects underwater.

Music

Sound waves are fundamental to the production and perception of music.

Also see

• Wave
• Acoustics
• Frequency
• Amplitude
• Ultrasound
• Sonar