The correct answer is: B. Deci
A decibel (dB) is a logarithmic unit that expresses the ratio of a physical quantity (such as sound pressure) to a reference value. The reference value is often 0 dB, which is the threshold of human hearing.
A phon is a unit of perceived loudness, not sound pressure. It is based on the subjective response of human hearing, and is not directly proportional to sound pressure level.
A decibel is a unit of sound pressure level, which is a measure of the intensity of a sound. The decibel scale is logarithmic,
which means that a change of 10 dB represents a tenfold increase in sound pressure.A decimal is a number that is written using the decimal system, which is a system of counting that uses ten as the base. The decimal system is the most common system of counting in use today.
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