Science and Technology K–6 · Years 1–2
Loud and soft: more energy, bigger vibration
Physical World, energy comes in different forms that can be detected (NSW 2017); Science understanding, Physical sciences, and Science as a human endeavour (ACARA v9)
The idea
Putting more energy into an object makes a bigger vibration and a louder sound, and a sound-level meter turns that into a number the class can compare with its own other readings.
What you need
- A drum (or an upturned plastic tub) and a beater
- A free sound-level meter app on a tablet set 1 m from the drum on a chair. A free app on a tablet is not a calibrated meter, so its readings are used to compare one strike with the next and never read as a decibel figure for the sound itself
- A ruler to set the beater's drop height: 5 cm, 15 cm, 30 cm above the skin
- Recording table: drop height, meter reading (dB), three strikes each
How to do it
- Let the beater fall onto the skin from 5 cm. Read the highest number the meter shows. Three strikes.
- Repeat from 15 cm and from 30 cm.
- Circle the middle reading for each height and draw a bar for each.
- Make a classroom noise meter: read the meter during silent reading, during group work and at the door at recess.
- Say which of the three classroom readings was the highest and which the lowest, and where else in the school you would expect a higher one.
What you should see
The middle readings rise with the drop height of the beater: the 30 cm strike reads highest and the 5 cm strike lowest, because a longer drop gives the beater more energy to hand to the skin. The three classroom readings are compared as the class records them. The exact decibel values belong to the room and the app; the order is the result. Judging a sound against a hearing-safety level needs a calibrated meter, which a free app is not, so the class compares its own readings with each other and reads no safety figure out of them. The learner knows it worked when the three bars rise with drop height.
What changes
- What you change
- drop height of the beater (5, 15, 30 cm)
- What you measure
- meter reading (dB)
- What you keep the same
- same drum and beater
- meter 1 m away
- three strikes each
Common misconceptions
Each of these ideas is wrong, and the activity is a chance to test it.
- A louder sound is a higher sound.
- Sound has no energy because you cannot see it.
Safety card
Hazards
- Loud sounds close to ears
Controls
- Drum struck from a drop, not swung; no ears within 30 cm of the drum
Note
No chemicals or heat. Record the activity on the school's risk assessment (Primary School RiskAssess, Ecosolve Australia, riskassess.com.au).
Curriculum references
The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.
- Science and Technology K-6 Syllabus (2017), NESA. Current syllabus; NESA's timeline is 2026 plan and prepare, 2027 start teaching the 2024 syllabus. Code read from the official syllabus document on 2026-09-22.ST1-8PW-SST1-1WS-S
- Science and Technology K-6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the outcomes page on 2026-09-22.ST1-SCI-01ST1-DAT-01
- Australian Curriculum v9AC9S2U02AC9S2H01AC9S2I02AC9S2I03AC9S2I04
Sources
The pages the author read to write this activity.