Practice reading decibel levels, comparing sound intensity, and making safe choices for sound design and hearing protection.
Read each problem carefully. Use the decibel safety rules provided in the questions. Show your work in the space provided.
Understanding sound levels, loudness, and safe listening habits
Physics - Grade 6-8
- 1
A whisper is about 30 dB, a normal conversation is about 60 dB, and a busy street is about 80 dB. Put these sounds in order from quietest to loudest.
- 2
A sound designer is choosing between two sound effects. Effect A is 70 dB and Effect B is 90 dB. Which effect has the higher sound level, and by how many decibels?
- 3
Decibels use a special scale. A sound that is 10 dB higher has 10 times greater intensity. How many times greater in intensity is an 80 dB sound than a 70 dB sound?
- 4
A school dance has music at 95 dB. The recommended safe exposure time at 95 dB is about 1 hour. If the dance lasts 3 hours, what is one safe choice students could make?
- 5
Look at this hearing safety guide: 85 dB is safe for about 8 hours, 88 dB for about 4 hours, 91 dB for about 2 hours, and 94 dB for about 1 hour. What pattern do you notice as the sound level increases by 3 dB?
- 6
Using the 3 dB safety pattern, if 94 dB is safe for about 1 hour, about how long is 97 dB safe?
- 7
A student listens to headphones at 100 dB. Another student listens at 70 dB. The difference is 30 dB. Using the rule that every 10 dB means 10 times greater intensity, how many times greater is the intensity at 100 dB than at 70 dB?
- 8
A sound designer wants a background ocean sound to be calming and not cover the actors' voices. The actors' voices are around 65 dB. Should the ocean sound be closer to 45 dB or 85 dB? Explain.
- 9
A concert speaker is 105 dB near the stage. A student says, 'It is only 20 dB louder than 85 dB, so it is only a little more dangerous.' Explain why this idea is incorrect.
- 10
A sound level meter shows these readings in a cafeteria: 78 dB, 82 dB, 84 dB, 83 dB, and 81 dB. What is the highest reading, and is it below or above 85 dB?
- 11
A video editor adds a loud explosion sound effect to a scene. The explosion sound peaks at 110 dB. Name two reasons the editor should lower the volume before showing the video to a class.
- 12
The chart shows approximate sound levels: library 40 dB, classroom 60 dB, vacuum cleaner 75 dB, lawn mower 90 dB, and rock concert 110 dB. Which two sounds are most likely to require hearing protection if you are near them for a long time?
- 13
A student uses earplugs that reduce sound by 15 dB. If the sound at a pep rally is 100 dB, what sound level reaches the student's ears while wearing the earplugs?
- 14
A theater group places a speaker very close to the front row. List two sound design changes that could make the show safer while still allowing the audience to hear clearly.
- 15
Write a short safety rule for students using headphones during music editing. Your rule should mention both volume and time.