Activity 2 - Sound

Activity objectives

A. To understand how sound is produced and detected.

B. To differentiate pitch and loudness.

C. To estimate age based on hearing limit.

D. To determine an unknown frequency using beat.

Pre-activity

Install Physics Toolbox Sensor
Prepare access to https://www.szynalski.com/tone-generator/ 

PART A

1. Knock the tuning fork. Bring it near your ear.

2. Knock it again, and touch its end.

3. Could you think about how sound is produced? What is sound?

4. Confirm your understanding with the simulation: https://physlets.org/pp/oscillations_waves/sound/illustration18_2.html

5. Look at the ear anatomy below. How is sound detected?

6. Let us appreciate our hearing ability. https://youtu.be/lOJwY6UlBc0?si=LZGtrNy-wh3FAvxu

PART B

1. Knock both tuning forks. Compare the sound they produce. 

(i) Which one has the higher pitch? 

(ii) Which produced a higher sound frequency? 

2. Identify the microphone on your device. Open the Physics Toolbox (oscilloscope) and compare the signal shapes at the two frequencies, f1 and f2.

3. Open Physics Toolbox (tone detector/osciloscope/spectrum analyser), determine the value of those frequencies.

4. Choose one of the tuning forks. Open the Physics Toolbox (oscilloscope) and compare the signal shapes at the two frequencies. What is the relation between loudness and the amplitude of the signal?

5. Open Physics Toolbox (tone generator), reproduce f1 and f2. 

6. Both sound pitch and loudness are in the Form 2 Science, as below.

7. Determine whether the sound is loudness or pitch versus time. https://youtube.com/shorts/ykMVH5tnc-g?si=pRYjrMAj81Lv8nMy

PART C

1. Raise your hand. Listen carefully to the sound produced by the instructor. (https://onlinetonegenerator.com/hearingtest.html)

2. When you notice that you cannot hear the sound, read the frequency and lower your hand.

3. Estimate your age, does it correlate to the frequency limit?

4. We do have hearing limit, generally as show below.

Non-toxic repellant.