Sound is produced when an object vibrates, causing the surrounding air molecules to vibrate as well.

Frequency is measured in Hertz (Hz) and determines the pitch of a sound.

Amplitude is the maximum displacement of a sound wave from its equilibrium position and is related to the intensity of the sound.

In a sound wave, the frequency and wavelength are inversely proportional, meaning that as one increases, the other decreases.

The speed of sound in air at room temperature is approximately 343 meters per second.

Reflection is the bouncing back of sound waves from a surface.

Diffraction is the bending of sound waves around obstacles.

Absorption is the process by which sound waves are converted into other forms of energy, such as heat.

Interference is the combination of two or more sound waves, resulting in a new wave pattern.

Resonance is the reinforcement of sound waves due to constructive interference.

Beats are the periodic variation in loudness caused by the interference of two sound waves.

Harmonics are integer multiples of the fundamental frequency. The first three harmonics of a sound wave with a fundamental frequency of 100 Hz are 100 Hz, 200 Hz, and 300 Hz.

Timbre is the quality of a sound that distinguishes it from other sounds with the same pitch and loudness. It is determined by the overtones, which are the frequencies present in addition to the fundamental frequency.

The Doppler effect is the change in frequency of a sound wave due to the relative motion between the source and the observer.

The threshold of hearing is the minimum intensity of sound that can be detected by the human ear.