By: Jessica Fink

1. Whydoes Helium make your voice sound higher, and which amount of Helium works better to change the sound of your voice; a full amount or small amount? By: Jessica Fink

2. Purpose/Problem: Why does Helium make your voice sound higher, and which amount of Helium works better to change the sound of your voice; a full amount or small amount? I performed this experiment to show how one’s voice changes when breathing in Helium, and the reason behind it.

3. My Knowledge and Research Helium Atom You can take a breath of Helium to change the sound of your voice and demonstrate how density affects the spread of sound. As you talk or sing after breathing in Helium, your vocal cords vibrate and the sound waves are produced through helium instead of air. Your vocal cords simply vibrate differently in the lighter gas. Helium sound waves are actually 6 times lighter and denser than regular oxygen (this is why balloons float); therefore, they travel much faster than air during the short period of time that it takes for them to make their way out of the throat and mouth. The pitch of our voice doesn’t change when breathing in helium, but the quality of our voice does. The quick-moving higher frequency sounds have more power as they float in your throat, and the lower frequencies tend to get lost, causing the voice to sound flat.

4. My Hypothesis Based on my research, I think that breathing in a full breath of helium would cause a greater change in my voice because it would allow a greater amount of denser air to reach my vocal cords and cause a stronger and more noticeable vibration.

5. Materials and Procedures Procedures: Obtain the balloon full of Helium and cut a small slit in the bottom of the balloon where the plastic is the skinniest. Hold the balloon closed with your hand until you are ready to breath the Helium so that no Helium escapes. Let as much air out of your body as you can and breathe in Helium. The first time, breathe a quick, small amount of Helium, talk, and record what your voice sounds like. The second time, take a full, slow breath of Helium and record your results. Materials needed: One or two balloons A person to breathe the Helium A pair of scissors to slit a hole in the bottom of the balloon

6. Results and data (Analysis) Independent Variable: Amount of Helium breathed in. Dependent Variable: The change in my voice. Control: Helium.

7. Analysis Continued After completing this experiment, I realized that there is a lot more to Helium than I thought. I never exactly knew how Helium worked, and certainly never knew what happens when Helium hits your vocal cords. I also witnessed the change in my tone of voice as I breathed in the Helium, and surprisingly knew how the Helium affected my voice because of taking time to research. This experiment helped me realize that Helium may change your tone of voice, but doesn’t change the pitch; which turns out sounding much like Donald Duck or a chipmunk. If I were to repeat this experiment over, I would use different periods of time to breathe each amount of air in, and have more than one person breathe the Helium to show how it can affect people differently.

8. Conclusion: In this experiment, I used Helium to show the difference in density, in comparison with regular oxygen that we breathe on a daily basis. I changed the amount of Helium that would get breathed in each time, and realized that the amount of Helium I attempted to breathe in also determined how quickly I would breathe it in as well. The second thing I noticed was that I felt a slight tickle in my throat when breathing in the Helium and talking when I was exhaling. This probably occurred because of the myth that Helium vibrates your spinal cords differently, and possibly quicker than oxygen does. The Helium’s light density made it want to float right out of my throat, which is also why the Helium didn’t want to keep my voice changed for a long period of time. The changed voice lasted about 5-10 seconds. In conclusion, I think that this experiment was both fun and educational, which was mainly because of previous research and physical tests.

9. Resources: • http://chemistry.about.com/od/chemistryactivities/a/Helium-Voice.html • http://ilovebacteria.com/helium.html