Lesson Plan

• Describe how amplitude influences the loudness of a sound wave.
• Explain how frequency determines the pitch of a sound.
• Compare the perceptual effects when both amplitude and frequency change simultaneously.
• Apply the decibel formula to calculate relative loudness.
• Identify common misconceptions about the relationship between loudness and pitch.

• Projector and screen
• Computer with sound‑wave simulation software
• Speakers or a loudspeaker
• Printed worksheet / handout
• Frequency generator or tuning forks
• Volume (amplitude) control demo device
• Whiteboard and markers

Begin by asking students to think of the difference between a whisper and a whistle. Review that sound is a vibration travelling through a medium and that they have already explored wave concepts. Explain that today they will discover how the size of the vibration (amplitude) and the speed of the vibration (frequency) shape what we hear. Success will be measured by their ability to explain the loudness‑pitch relationships.

1. Do‑now (5'): Write examples of sounds that are loud versus sounds that are high‑pitched.
2. Mini‑lecture with slides (10'): Define amplitude, frequency, loudness and pitch; introduce I ∝ A² and L = 10 log₁₀(I/I₀).
3. Demonstration (10'): Use the speaker and tone generator to vary amplitude while keeping frequency constant, then vary frequency while keeping amplitude constant; students note observations.
4. Guided practice (10'): Worksheet calculations of decibel changes and identification of pitch from frequency values.
5. Group activity (10'): Students use tuning forks or a mobile app to create sounds with different amplitudes and frequencies and discuss combined effects.
6. Misperception check (5'): Quick Kahoot quiz on common misconceptions.
7. Summary & exit ticket (5'): Write one sentence summarising how amplitude affects loudness and how frequency affects pitch.

Recap that larger amplitude raises intensity and therefore loudness, while higher frequency raises pitch. Collect the exit‑ticket sentences to gauge understanding and assign a short homework: complete an online simulation exploring amplitude‑frequency changes and answer three reflection questions.