Decibels report _______.

Decibels report _______.

• A. Absolute numbers
• B. Relative changes
• C. Both
• D. None

Answer: (B)

Decibels report relative changes because a decibel is a logarithmic unit that expresses a ratio to a reference level. It doesn’t give an absolute amount on its own; instead it shows how large or small a quantity is compared with that fixed reference. The logarithmic nature also makes multiplication in the actual quantity become addition in the dB scale, which is why we talk about changes in level more conveniently. For example, doubling power is about a 3 dB increase, while a tenfold change in power is about 10 dB. So the key idea is that decibels quantify how one level compares to another, i.e., a relative change.

Decibels report relative changes because a decibel is a logarithmic unit that expresses a ratio to a reference level. It doesn’t give an absolute amount on its own; instead it shows how large or small a quantity is compared with that fixed reference. The logarithmic nature also makes multiplication in the actual quantity become addition in the dB scale, which is why we talk about changes in level more conveniently. For example, doubling power is about a 3 dB increase, while a tenfold change in power is about 10 dB. So the key idea is that decibels quantify how one level compares to another, i.e., a relative change.