Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency. The period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. For example, if a newborn baby's heart beats at a frequency of 120 times a minute, its period – the interval between beats – is half a second (60 seconds (i.e., a minute) divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio (sound) signals, radio waves, and light.
For cyclical processes, such as rotation, oscillations, or waves, frequency is defined as a number of cycles per unit time. In physics and engineering disciplines, such as optics, acoustics, and radio, frequency is usually denoted by a Latin letter f or by the Greek letter or ν (nu) (see e.g. Planck's formula).
The period, usually denoted by T, is the duration of one cycle, and is the reciprocal of the frequency f:
Frequency is a music video game developed by Harmonix and published by SCEA. It is the first major release from Harmonix. It was released in November 2001. A sequel titled Amplitude was released in 2003.
In the game, a player portrays a virtual avatar called a "FreQ", and travels down an octagonal tunnel, with each wall containing a musical track. These tracks contain sequences of notes. As the player hits buttons corresponding to the note placement on the track, the "sonic energy" from within is released and the music plays. If the player plays two measures of the track without any errors, the track is "captured" and the music plays automatically until the next pre-determined section of the song. All songs featured in the game are edited for ease of play.
Some tracks are bonus tracks and only open up when all notes are played, allowing the user to pick up "freestyle" points. Powerups are available which allow the immediate capturing of the track or the doubling of points. If a player continually misses notes, their energy meter reduces until the game is over.
In physics, sound is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a medium such as air or water. In physiology and psychology, sound is the reception of such waves and their perception by the brain.
Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an acoustician, while someone working in the field of acoustical engineering may be called an acoustical engineer. An audio engineer, on the other hand is concerned with the recording, manipulation, mixing, and reproduction of sound.
Applications of acoustics are found in almost all aspects of modern society, subdisciplines include aeroacoustics, audio signal processing, architectural acoustics, bioacoustics, electro-acoustics, environmental noise, musical acoustics, noise control, psychoacoustics, speech, ultrasound, underwater acoustics, and vibration.
Before I was undiscovered
When I was invincible
Nobody could kill the silence
And probably no one will again
The future was unrelated
Alternatives all pursued
The lives that got separated
When others were split in two
And I don’t remember now where I’m,
Supposed to be
I slide between the waves,
And ride the frequency alone
They might have agreed to listen
If I didn’t loose control
But I was as lost as they were
As still as a heart grown cold
And I don’t recall how I became
The one I used to be
I heard the strings of life begin
Within the frequency that night
I walked through the walls
Hold on tight, lives are going to change
The kind of his kingdom is surely falling out of range
Stay a while in the present tense
All in good time,
You’ll find your inner sense
Now as a final fire climbs into the
Single spire
High above the wireless world it hovers
So as the brightest child sinks into the safest arms
Tight against the bomb that hangs above us
I could of stayed if you were mine
If time remained the reasons would of rhymed
But I don’t remember now where I should be
Find me where you don’t believe me
There’s a warning in between the memories
Can you hear me through the whitest noise?
I slide between the waves,
And ride the frequency
Light and sound
Conceal me
They shield me
From danger signs
Make me understand it