A bel (symbol B) is a unit of measure of ratios, such as power levels and voltage levels. It is mostly used in telecommunication, electronics, and acoustics. Invented by engineers of the Bell Telephone Laboratory to quantify the reduction in audio level over a 1 mile length of standard telephone cable, it was originally called the transmission unit or TU, but was renamed in 1923 or 1924 in honor of the laboratory's found ...

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Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - dB cheat sheet, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - History of bels and decibels

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Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - History of bels and decibels

An intensity I or power P can be expressed in decibels with the standard equation where I0 and P0 are a specified reference intensity and power. If PdB is 10 dB greater than PdB0 then P is ten times P0. If PdB is 3 dB greater, the power r ...

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Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - Definition

Decibel - Acoustics. The decibel unit is often used in acoustics to quantify sound levels relative to some 0 dB reference. The reference may be defined as a sound pressure level (SPL), commonly 20 micropascals (20 μPa). To avoid confusion with other decibel measures, the term dB(SPL) is used for this. The reference sound pressure (corresponding to a sound pressure level of 0 dB) can also be defined as the sound pressure at the threshold of human hearing, which is conventionally taken to be 2×10−5 newtons per square metre, or 20 micropascals. That is roughly the soun ...

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Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - dB cheat sheet, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - Uses

Decibels are handy for mental calculation, because adding them is easier than multiplying ratios. First, however, one has to be able to convert easily between ratios and decibels. The most obvious way is to memorize the logs of small primes, but there are a few other tricks that can help. Decibel - Round numbers. The values of coins and banknotes are round numbers. The rules are: One is a round number Twice a round number is a round number: 2, 4, 8, 16, 32, 64 Ten times a rou ...

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Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - dB cheat sheet, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - Reckoning

Decibel - Absolute measurements. dBm or dBmW  dB(1 mW) — power measurement relative to 1 milliwatt. dBW  dB(1 W) — same as dBm, with reference level of 1 watt. dBu or dBv  dB(0.775 V) — (usually RMS) voltage amplitude referenced to 0.775 volt. Although dBu can be used with any impedance, dBu = dBm when the load is 600Ω. dBu is preferable, since dBv is easily confused with dBV. The "u" comes from "unlo ...

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Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - dB cheat sheet, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - Typical abbreviations

Bel can mean: Bel (god), a Semitic deity Bel or Belenus; an alternate name of the Celtic deity Bel or decibel; a unit of measurement for sound levels Bel or Bael; a tree (or its fruit) native to India Bel, fictional lord of the first of The Nine Hells, in Dungeons and Dragons games See also. BEL Bell Belle ...

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An intensity I or power P can be expressed in decibels with the standard equation where I0 and P0 are a specified reference intensity and power. If PdB is 10 dB greater than PdB0 then P is ten times P0. If PdB is 3 dB greater, the power r ...

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Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - dB cheat sheet, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - Definition

Sound pressure level (SPL) or sound level Lp is a logarithmic measure of the rms pressure (force/area) of a particular noise relative to a reference noise source. It is usually measured in decibels (dB(SPL), dBSPL, or dBSPL). where p0 is the reference sound pressure and p1 is the sound pressure being measured. A common reference sound pressure is p0 = 20 m ...

Including:

Sound pressure level - Measuring sound pressure levels Sound pressure level - SPL in audio equipment

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The word unity simply means oneness and is used in a variety of ways. In science and technology, unity could refer to: unity in mathematics refers to the number one. This also extends to electrical engineering, particularly to audio (see unity gain). Expressed in decibels, unity is 0dB. The Unity Module, a segment of the International Space Station. UNITY, a programming language. Unity, or unity of in ...

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Sound power or acoustic power Pac is a measure of sonic energy E per time t unit. It is measured in watts, or sound intensity I times area A: The measure of a ratio of two sound powers is where P1, P0 are the sound powers. The sound power level PWL, LW, or LPac of a source is expressed in decibels (dB) and is equal to 10 times the logarithm to the base 10 of the ratio of the sound power of the source to a refere ...

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Level has more than one meaning. A noun meaning "degree" or "extent" (particularly of competence or skill): In computer and video games, particularly role-playing games: "levels" represent skill and experience; see experience point "leveling" is the process of gaining levels, a common activity in MMORPGs In language education, see Interagency Language Roundtable scale Sound pressure level is a measure related to Decibels A noun mea

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Silence is a relative or total lack of sound. An environment with sound below 20 decibels is considered quiet or silent. Silence - As a mark of respect. Further information: Moment of silence Silence has been a part of the rituals surrounding Armistice Day since its inception, after the idea was first proposed by an Australian journalist, Edward George Honey, and later implemented by King George V of the United Kingdom. A two-minute silence is held at 11am, "the elev ...

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Silence - As a mark of respect Silence - Gestures and symbols Silence - In music Silence - In debate Silence - In law

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A cepstrum (pronounced "kepstrum") is the result of taking the Fourier transform (FT) of the decibel spectrum as if it were a signal. There is a complex cepstrum and a real cepstrum. The cepstrum was defined in a 1963 paper (Tukey et al.). It may be defined verbally: the cepstrum is the FT of the log (with unwrapped phase) of the FT mathematically: cepstrum of signal = FT(log(FT(the signal))+j2πm) (where m is the integer required to properly unwrap the angle or imaginary part of the complex log function. algorithmically: signal → FT → log ...

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Cepstrum - Applications Cepstrum - Etymology

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In electronics, gain is usually taken as the mean ratio of the signal output of a system to the signal input of the system. A gain of five would imply that either the voltage or power is increased by a factor of five. It has wide application in amplifiers. In electronics, it is common to use logarithmic units to measure gain. Originally, the bel was used: Gain = log10 (P2/P1) bel This unit turned out to be too large, so the decibel (one tenth of a bel) became popular in its place. As t ...

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Gain - Gain of an antenna

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DB or db or dB may stand for: Database, an organized collection of data DB (car), a French automobile maker Decibel (dB), the ratio between two quantities, used in acoustics and electronics Deutsche Bahn, the major German railway company Deutsche Bank, a German bank Deutsche Bundesbahn, the national railway company of the former West Germany Discovery Bay, a residential development in Lantau Island, Hong Kong Dubnium (Db), symbol for the chemical

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In electronics, cutoff frequency (fc) is the frequency either above which or below which the power output of a circuit, such as a line, amplifier, or filter, is reduced to 1/2 of the passband power; the half-power point. This is equivalent to a voltage (or amplitude) reduction to 70.7% of the passband, because voltage V2 is proportional to power P. This happens to be close to −3 decibels, and the cutoff frequency is frequently referred to as the −3 dB point. Also called the knee frequency, d ...

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Sound is vibration, as perceived by the sense of hearing. We usually hear vibrations that travel through air, but sound can also travel through gases, liquids and solids. It cannot travel through a vacuum (such as exists in outer space). When the vibrations reach our ears, they are converted into nerve impulses that are sent to our brains, allowing us to perceive the sound. In more technical language, sound "is an alternation in pressure, particle displacement, or particle velocity propagated in an elastic material" (Olson 1957 ...

Including:

Sound - Attributes of sound
Sound - Frequency and wavelength Sound - Amplitude Sound - Velocity
Sound - Types of sounds Sound - Perception of sound
Sound - Sound measurement

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Decibels are handy for mental calculation, because adding them is easier than multiplying ratios. First, however, one has to be able to convert easily between ratios and decibels. The most obvious way is to memorize the logs of small primes, but there are a few other tricks that can help. Decibel - Round numbers. The values of coins and banknotes are round numbers. The rules are: One is a round number Twice a round number is a round number: 2, 4, 8, 16, 32, 64 Ten times a rou ...

See also:

Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - Reckoning

Decibel - Acoustics. The decibel unit is often used in acoustics to quantify sound levels relative to some 0 dB reference. The reference may be defined as a sound pressure level (SPL), commonly 20 micropascals (20 μPa). To avoid confusion with other decibel measures, the term dB(SPL) is used for this. The reference sound pressure (corresponding to a sound pressure level of 0 dB) can also be defined as the sound pressure at the threshold of human hearing, which is conventionally taken to be 2×10−5 newtons per square metre, or 20 micropascals. That is roughly the soun ...

See also:

Decibel, Decibel - Definition, Decibel - Standards, Decibel - Merits, Decibel - History of bels and decibels, Decibel - Uses, Decibel - Acoustics, Decibel - Electronics, Decibel - Optics, Decibel - Telecommunications, Decibel - Seismology, Decibel - Typical abbreviations, Decibel - Absolute measurements, Decibel - Relative measurements, Decibel - Reckoning, Decibel - Round numbers, Decibel - The 4 → 6 energy rule, Decibel - The 789 rule, Decibel - −3 dB ≈ ½ power, Decibel - 6 dB per bit, Decibel - Reference

Read more here: » Decibel: Encyclopedia II - Decibel - Uses