Acoustics is the scientific study of sound, including its production, propagation, and perception.

Audition is the process by which sound waves are converted into electrical signals that are interpreted by the brain.

The frequency range of human hearing is generally considered to be from 20 Hz to 20 kHz, although some people may be able to hear frequencies outside of this range.

Sound intensity is measured in decibels (dB), which is a logarithmic unit that expresses the ratio of a sound's intensity to a reference level.

The absolute threshold is the minimum sound intensity that can be detected by the human ear under ideal conditions.

The dynamic range is the difference between the absolute threshold and the pain threshold, which is the maximum sound intensity that can be tolerated by the human ear without causing pain.

Pitch is the perception of the frequency of a sound, which is determined by the number of sound waves that reach the ear per second.

Loudness is the perception of the intensity of a sound, which is determined by the amplitude of the sound waves.

Timbre is the perception of the quality of a sound, which is determined by the shape of the sound wave.

Harmony is the perception of the pleasing combination of two or more sounds.

Tinnitus is the perception of a sound that is not actually present, which can be caused by a variety of factors, including ear damage, stress, and certain medications.

The loudness illusion is the phenomenon of hearing a sound as louder or softer than it actually is, which can be caused by a variety of factors, including the context in which the sound is heard and the listener's expectations.

The pitch illusion is the phenomenon of hearing a sound as higher or lower in pitch than it actually is, which can be caused by a variety of factors, including the context in which the sound is heard and the listener's expectations.

The timbre illusion is the phenomenon of hearing a sound as having a different timbre than it actually does, which can be caused by a variety of factors, including the context in which the sound is heard and the listener's expectations.

The harmony illusion is the phenomenon of hearing a sound as being more or less harmonious than it actually is, which can be caused by a variety of factors, including the context in which the sound is heard and the listener's expectations.