Definition of Frequency
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light.
The interval of time between events is called the period. It is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second.
Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or occur repeatedly in geometry or space.
Terms mentioned above
Related terms
Speed of sound
The speed of sound is the distance travelled per unit of time by a sound wave as it…
Audio frequency
An audio frequency or audible frequency (AF) is a periodic vibration whose frequency is…
Sound power
Sound power or acoustic power is the rate at which sound energy is emitted, reflected…
Place theory
Place theory is a theory of hearing that states that our perception of sound depends on…
Temporal envelope and fine structure
Temporal envelope (ENV) and temporal fine structure (TFS) are changes in the amplitude…
Acoustical engineering
Acoustical engineering (also known as acoustic engineering) is the branch of engineering…
Rumble (noise)
A rumble is a continuous deep, resonant sound, such as the sound made by heavy vehicles…
Phonon
A phonon is a quasiparticle of vibrational energy that uniformly oscillates at a single…
Proximity effect (audio)
The proximity effect in audio is an increase in bass or low frequency response when a…
Questions people ask
Real questions from the Stack Exchange community – follow a link to read the discussion.
- Why are the harmonics of a piano tone not multiples of the base frequency? · Physics SE
- Do low frequency sounds really carry longer distances? · Physics SE
- Why does medium not affect the frequency of sound? · Physics SE
- How do headphones and earphones produce good bass if tiny speakers can't produce low frequency sounds very well? · Physics SE
- Over what frequency range can the microphone of smartphone receive the sound? · Electronics SE
- Does the human body have a resonant frequency? If so, how strong is it? · Physics SE
Frequently asked questions
What is Frequency?
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals (sound)…
Sources & credits
- Wikipedia: Frequency – CC BY-SA 4.0
- Image by Wikinana38 – CC BY-SA 4.0