# Sound characteristic

Physics > Sound characteristic

Explore characteristics and properties of sounds like waves: the movement of sound along sine waves, frequency, tone and amplitude, sound perception, speed of sound.

Sound – longitudinal pressure wave passing through space in liquid, solid, gaseous states or plasma.

## Learning challenge

• Understand how people characterize sound.

## Key points

• Sound is transported along longitudinal sine waves.
• Sound is characterized by its frequency, tone, and amplitude.
• The speed of sound travel is based on the environment. Can be calculated by the formula (K is the stiffness coefficient of the material, and p is the density of the material).

## Terms

• Media is a general term for a variety of types of materials.
• Hertz – measurement of audio frequency.
• Frequency is the ratio of the number of times (n) of a periodic event in time

Let s get to know the basics of sound. This is a longitudinal pressure wave passing through compressible spaces. In a vacuum (free from particles and matter), sound is impossible. Vacuum has no medium, so sound simply cannot move.

Sound characteristics:

• It is transported along longitudinal waves. When graphically depicted, they are shown as sinusoidal.
• Have a frequency (the height rises and falls).
• Amplitude describes the loudness.
• Tone is an indicator of the quality of a sound wave.
• It is transported faster in hot environments than in solids. Higher at sea level (where air pressure is higher).
• Intensity is the energy transmitted in a specific area. It is also a measure of audio frequency.
• Ultrasound uses high-frequency waves to detect what is usually hidden (tumors). Bats and dolphins also use ultrasound to navigate and find objects. On ships, the same scheme is used.

## Sound perception

Each sound wave has properties, including length, intensity, and amplitude. In addition, they have a range, that is, the level of sound perception. For example:

• People: 20 – 20,000 Hz.
• Dogs: 50 – 45,000 Hz.
• Bats: 20 – 120,000 Hz.

It can be seen that among the three representatives, people have the lowest rate.

## Sound speed

Transport speed is based on medium. It rises in solid state and falls in liquid and gas. Formula: (K is the stiffness coefficient of the material and p is the density).

If it says “faster than sound speed”, then this is a comparison with an indicator of 344 m / s. The overall measurement is taken at sea level with a temperature mark of 21 ° C and under normal atmospheric conditions. Shown here is a plane moving faster than sound speed.

### Physics Section

Introduction
• Sound characteristics
• Sound wave frequency
• Sound production: vibrating string and air speakers
• Sound quality
• Sound speed
Sound intensity and sound level
• Intensity
• Human perception of sound
• Decibels
Doppler effect and sonic arrows
• Moving the observer
• Moving the source
• General case
• Sonic boom
Interacting with sound waves
• Superposition
• Interference
• Beating
• Ear
• Applications: ultrasound, sonar and medical imaging
Further topics
• Spherical and plane waves
• Standing waves on a string
• Standing waves in air poles
• Forced vibrations and resonance