Sound wave (acoustic) – a sound wave, or acoustic wave, is a type of disturbance. It occurs as a result of energy transfer through vibrating particles, which do not change their position or move. In this case, the vibrating particles are referred to as the elastic medium. As a result of the vibrations, there are temporary and dynamic changes in density and pressure, which can then be described as acoustic pressure and classified in decibels. This is how sounds are produced, which are then heard by humans.
Acoustic waves can be classified, among other things, based on their frequencies:
infrasound waves – below 16 Hz;
sound waves (heard by the human ear) – from 16 Hz to 20 kHz;
ultrasound waves – above 20 kHz;
hypersound waves – above 10^10 Hz.
Sound waves can have different lengths and shapes. In terms of shape, flat, cylindrical, and spherical waves are distinguished.
There is also a classification of sound waves based on their spectrum. Discrete and continuous spectra are distinguished.
Discrete spectra:
– simple (have a specific frequency)
– harmonic (have multiple tones and are periodic, including music and singing)
Continuous spectra:
– noise (sounds with a balanced range of audibility)
– din (sounds with excessive intensity of audibility).
