In the descriptions below, capital indicates an upper case Greek letter, while small indicates a lowercase Greek letter.
α (small alpha) – the symbol for an angular acceleration.
α-Fe2O3 – alpha ferric oxide. See ferric oxide.
β (small beta) – the symbol for an sound intensity.
γ (small gamma) – (1) The symbol for a photon. (2) Sometimes used as the symbol for conductivity.
γ-Fe2O3 – gamma ferric oxide. See ferric oxide.
Δ (capital delta) – (1) Symbol for a difference. For example, ΔT is used to represent a time difference. (2) The symbol for a major seventh chord in jazz music notation.
ΔΣ – see delta-sigma modulation.
ε (small epsilon) – the symbol for the electromotive force (EMF) of a circuit.
ζ (small zeta) – the symbol for the damping ratio.
η (small eta) – the symbol for the efficiency of a device, especially a power supply, which is defined as the output power divided by the input power.
θ (small theta) – (1) The symbol for an angle in one plane. (2) The symbol for phase angle.
ι (small iota) – represents not one iota.
κ (small kappa) – sometimes used as the symbol for conductivity.
λ (small lambda) – the symbol for wavelength.
μ (small mu) – (1) The symbol for the magnetic dipole moment of a current-carrying coil. (2) The symbol for magnetic permeability. (3) The symbol for micro-, an SI prefix meaning one millionth (10‑6). (4) The symbol for micron, a unit of length equal to one millionth of a meter. The more correct term is now micrometer (μm). (5) The symbol for the amplification factor or voltage gain of a triode vacuum tube.
μ-law algorithm – a companding algorithm, primarily used in 8-bit PCM digital audio signals. Companding algorithms reduce the dynamic range of an audio signal, but at an increased signal-to-noise ratio (SNR). Sometimes written as mu-law algorithm or u-law algorithm. See also au.
ν (small nu) – the symbol for the frequency of a wave in hertz (Hz).
π (small pi) – (1) A mathematical symbol for the ratio of the circumference of a circle to its diameter, approximately equal to 3.14159.... (2) Used to express angles in radians. A radian is the angle of an arc that is equal in length to the radius of the arc. Therefore, the magnitude in radians of one complete revolution (a circle or 360 degrees) is the length of the circumference divided by the radius, or 2πr/r, or 2π. Since 2π radians equals 360 degrees, one radian is equal to 180/π degrees. Because a sine wave can be expressed as x = sin(y) where y is expressed in radians, a sine wave is frequently expressed in radians using π.
Σ (capital sigma) – the mathematical symbol for a sum or the summation operator.
ΣΔ – see delta-sigma modulation.
σ (small sigma) – (1) The standard deviation of a probability distribution in statistics. (2) The symbol for conductivity. (3) The symbol for specific magnetic moment. (4) The symbol for particle displacement.
τ (small tau) – (1) The symbol for the time constant of any device, such as an RC circuit. (2) The symbol for an interval of time. (3) The symbol for the golden ratio, although phi (φ) is more common.
Φ (capital phi) – (1) The symbol for magnetic flux. (2) Symbol for the number of phases in a power system. For example, 1Φ is used for single phase and 3Φ for three phase. (3) A symbol used on some DAWs and consoles to indicate the switch for polarity inversion. (4) The symbol for the reciprocal of the golden ratio or 1/φ (See φ below.) (4) The symbol for electric potential.
φ (small phi) – (1) The symbol for the phase of a wave. (2) The symbol for the golden ratio.
Ω (capital omega) – the symbol for ohm.
ω (small omega) – (1) The symbol for resonant frequency. (2) The symbol for angular velocity or angular frequency.
Note: We believe this is the largest dictionary (glossary) of terms specific to usage within the recording industry that is currently available on the internet, with more than 8,500 entries, nearly 600 illustrations, and dozens of tables. Some of the terms have different or additional meanings in other situations, especially within the electronic, automotive, scientific, and computer industries. Of necessity there are obvious overlaps into other fields such as music, electronics, and computers, but such excursions are limited to information deemed pertinent to the knowledge required to operate and/or participate effectively in the workings of a recording studio. Also included are terms related to sound reinforcement (live performances) including wireless microphone technology because a working knowledge of that terminology is necessary for recording at live performance venues. Because recording studios also record audio for video and motion pictures (films), some terminology from those fields is included. Some scientific terms are included because they help explain studio terminology. For example, electromagnetism explains how microphones, loudspeakers, and guitar pickups work. Knowledge of radio waves and the radio frequency spectrum is needed to explain wireless devices. Any trademarks or trade names mentioned belong to their respective owners. The information contained in this dictionary is believed to be accurate at the time of publication. This information is subject to change without notice. The information was obtained from and cross-checked with a variety of sources that are believed to be reliable. However, Los Senderos Studio, LLC does not guarantee the accuracy or completeness of the information contained herein. Please contact us to report any errors, omissions, discrepancies, or broken links. Los Senderos Studio shall not be responsible for any consequences or damages arising out of the use of this information. Nothing in this glossary should be interpreted as legal advice. For a glossary providing information on legal and business matters for musicians, we suggest you consult Musicians Business Dictionary.
A note on alphabetical order: The terms in this glossary are alphabetical without regard to spaces and punctuation. For example, AM Radio follows amplitude. While this may seem to be at odds with other conventions, it eliminates confusion with words such as pickup, which is sometimes written as pick up or pick-up. In addition, all symbols such as &, -, or / are ignored. The entries on the number page (0-9) are listed in increasing value within each digit. For example, all of the entries beginning with 1 are listed before those starting with 2. For Greek letters (α-ω), the entries are in Greek alphabetical order.