Answers to Decibel Problems 1–4

1. Two tones have intensities of 10–6 W/m2 and 10–3 W/m2, respectively. What is their difference in intensity level in dB?

Answer: 30 dB.

2. What is the intensity level of each of the tones in question 1?

Answer: 60 dB and 90 dB.

3. The sound intensity at a certain location is 10,000 times that at another location. By how many dB do they differ?

Answer: 40 dB.

4. How many dB correspond to three just noticeable differences, each of a 25% increase in intensity?

Answer: 3 dB.

2013 Robert Chuckrow

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