Which statement is true about octave band analysis as described?

• A. It is used to analyze time-domain signals only.
• B. It is used to measure heart rate.
• C. It is used to gather information on energy of sound over a range of frequencies.
• D. It is used to freeze samples for preservation.

Answer: (C)

Understanding how sound energy is distributed across frequency bands is what octave band analysis does. It splits the sound spectrum into octave-wide bands and measures how much energy lies in each band, giving a clear picture of the energy distribution across frequencies rather than just a single frequency. This frequency-specific energy profile is essential for assessing noise characteristics, hearing risk, and how a sound source behaves across the spectrum, and it’s typically done with octave-band filters or a spectrum analyzer. It’s a tool about the spectrum of sound, not about time-domain signals alone, and it isn’t used for measuring heart rate or freezing samples for preservation.