Negative decibels describe signals that are ______ in strength or getting ______.

• A. Decreasing; Smaller
• B. Increasing; Larger
• C. Constant; Unchanged
• D. Fluctuating; Varying

Answer: (A)

Negative decibels indicate attenuation: the signal is weaker than the reference level. Decibels express a ratio on a logarithmic scale, so when the ratio is less than one, the logarithm is negative, signaling reduced strength. In practice, this means the signal is decreasing in strength or getting smaller. For power, the formula uses 10 log10 of the ratio, so if the output power is less than the reference, you get a negative value; for voltage or amplitude, 20 log10 of the ratio gives a negative result when the output is smaller than the reference. This all ties to the idea that negative dB values represent attenuation rather than amplification.