Observing the movements of vocal cords during speech in Sound – Class 8 Science Experiment
Chapter Name: Sound
Activity Name: Observing the movements of vocal cords during speech in Sound
Activity Description:
In this experiment, you will observe the movements of the vocal cords during speech. You will ask a friend to raise their neck and place a stretched chocolate wrapper across their mouth. Then, your friend will blow air forcibly on the wrapper in two different ways: once forcefully and once slowly. You will observe the changes in the movements of their throat during these two occasions.
Required Items:
- A chocolate wrapper
- A willing participant (your friend)
Step by Step Procedure:
- Ask your friend to raise their neck slightly.
- Stretch the chocolate wrapper across their mouth, ensuring it is taut.
- Instruct your friend to blow air on the wrapper forcibly in the first trial.
- Observe the movements in their throat during this trial.
- Ask your friend to blow air on the wrapper slowly in the second trial.
- Observe the movements in their throat during this trial as well.
Experiment Observations:
- During the first trial (forceful blowing), the voice box (vocal cords) gets tensed and produces a high sound. In contrast, during the second trial (slow blowing), the vocal cords are close to the normal position of the throat, and they produce a lower sound.
Precautions:
- Ensure your friend is comfortable and willing to participate in the experiment.
- Use a clean chocolate wrapper to avoid any hygiene issues.
- Make sure the wrapper is stretched tightly across the mouth for accurate observations.
Lesson Learnt from Experiment:
The sound produced during speech is influenced by the movements of the vocal cords. Forceful blowing tenses the vocal cords, resulting in a higher pitch sound, while slower blowing relaxes the vocal cords, leading to a lower pitch sound. The sound we produce during speech is a combination of vibrations from the chocolate wrapper and the movements of the vocal cords.
