Which measurement concept does not filter or weight noise and tells the true dB level?

• A. Flat Response
• B. A-Weighting
• C. C-Weighting
• D. Standard noise exposure

Answer: (A)

The measurement concept here is about whether the frequency content is modified before reporting the decibel level. A flat response means no weighting filter is applied, so the reading reflects the true, unaltered sound pressure level across frequencies. A-weighting and C-weighting intentionally shape the spectrum to approximate human hearing or specific measurement goals, which changes the reported dB from the raw physical level. Standard noise exposure isn’t a weighting scheme itself, so it doesn’t describe how the measurement is reported. Therefore, the unweighted, flat response provides the true dB level.