Decibel (Db): One tenth of a Bel. This is a measurement of the comparative strength of two powers, and can be applied when measuring any signal in the audio, video, and electromagnetic spectrum. If two powers differ by one Bel, there is a difference of 10 times the power. If comparing amplifiers, where one is rated at 10 watts while the other is 100 watts, then we have a difference of 10 decibels, or one Bel. Decibels should be understood as ratios, not fixed quantities. Decibels are the preferred method and term for representing the ratio of different audio levels. It is a mathematical shorthand that uses logarithms (a shortcut using the powers of 10 to represent the actual number) to reduce the size of the number. For example, instead of saying the dynamic range is 32,000 to 1, we say it is 90 db [the answer in db equals 20 log x/y, where x and y are the different signal levels]. Being a ratio, decibels have no units. Audiologists generally assert that 1 decibel is the smallest difference in volume that can be heard by the average person. The term is derived as an honor to Alexander Graham Bell, who invented the telephone, and did much of the preliminary work in the modern science of acoustics.

 

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Decibel (Db): One tenth of a Bel. This is a measurement of the comparative strength of two powers, and can be applied when measuring any signal in the audio, video, and electromagnetic spectrum. If two po . . . View Full Definition

Dubnium (Db): Atomic number: 105, Atomic mass: 261.9 g.mol -1, Electronegativity: unknown, Density: unknown, Melting point: unknown, Boiling point: unknown, Vanderwaals radius: unknown, Ionic radius: unkn . . . View Full Definition

Defensive Back (DB): A cornerback or safety position on the defensive team; commonly defends against wide receivers on passing plays. Generally there are 4 defensive backs playing at a time.