The Effect of Relative Position on Decibel Readout

Student: Shriya Gutta
Table: 2
Experimentation location: Home
Regulated Research (Form 1c): No
Project continuation (Form 7): No




- Foundation, C. K.-12. (n.d.). 12 foundation. CK. Retrieved October 21, 2022, from          2.0/section/12.3/primary/lesson/intensity-and-loudness-of-sound-ms-ps/

- Clason, D. (2021, December 27). What is a decibel? Healthy Hearing. Retrieved October 21, 2022, from                                                        

- Zavisa, J. (2020, March 27). How special relativity works. HowStuffWorks Science. Retrieved October 21, 2022, from                                    

Additional Project Information

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Project files

Research Plan:


  • Speaker
  • Decibel X app 
  • Recorder 
  • Remote control car 
  • Stopwatch
  • Masking Tape
  • Sound Recording Device
  • Extra people for help



  1. Bring out a roll of masking tape.
  2. Go to an open area with a flat surface.
  3. Mark a center point with a piece of masking tape.
  4. Label this piece of tape the “centerpiece.”
  5. Get a sound recording device.
  6. Place a sound recording device on the “centerpiece.”
  7. Download the app called, “Decibel X”, (which lets you measure the decibel scale of a sound.)
  8. Place the device with the app parallel to the sound recording device.
  9. Rip out more pieces of masking tape.
  10. Place the masking tape in seven positions in a horizontal line in front of the “centerpiece”.
  11. Three of the positions will be to the right of the “centerpiece” and the other three will be on the left.
  12. The seventh piece of tape will be placed vertically parallel to the “centerpiece.”
  13. Label all of the seven pieces of masking tape as different levels of the IV.
  14. Bring out a remote control car.
  15. Make sure that the speed stays constant.
  16. Then place the remote control car so that it will pass all of the positions.
  17. Label this place the “starting position”.
  18. Get a stopwatch to time it and know what the decibel scale was for each position.
  19. Reset the car and repeat this process three times for each level.
  20. Make sure to record the data.



  • Risk of damaging ears with a sound with a very high decibel scale.
  • Risk of getting electrocuted with the remote control.



For my experiment, I measured the decibel readout of 11 relative positions. In conclusion, the hypothesis was accepted. According to the data table, the decibel readout when the siren was one foot to the left of the control was higher than the decibel readout when the siren was one foot to the right of the control. For example, when it was one foot to the left of the control, the decibel readout was 111.4 decibels. However, when it was one foot to the right of the control, the decibel readout was 92.4 decibels. Even though the hypothesis was accepted, there were a couple of errors noted in the procedure. The first random error is the angle at which the metric ruler was when the different sections were measured. This could have led to inaccurate measurements. Another random error could be in the relationship between the stopwatch and the decibel reader. If the decibel number was recorded at the wrong time, the data table and graph would be affected. The last random error is that the speaker used was a professional-grade speaker. Therefore, there were pauses in the siren sound a couple of times. One systemic error could have been that the decibel reader app was not completely accurate due to some of the ambient noise. This would have led to inaccurate measurements throughout the whole experiment.


Questions and Answers

1. What was the major objective of your project and what was your plan to achieve it? 

       a. Was that goal the result of any specific situation, experience, or problem you encountered?  

       b. Were you trying to solve a problem, answer a question, or test a hypothesis?

My goal was for my hypothesis to be accepted, and it was the result of my experiment. In my project, I was trying to answer a question and test a hypothesis. The question that was asked in this experiment is "How does the relative position affect the decibel readout"? The answer to this question is that as the relative position approaches the decibel meter, the decibel readout gets higher. This leads to my hypothesis which was "If the relative position is approaching the decibel meter, then the decibel readout will be higher". This hypothesis was accepted.


2. What were the major tasks you had to perform in order to complete your project?

       a. For teams, describe what each member worked on.

One of the major tasks I had to perform was the fact that I had to start a sound recording device, a stopwatch, and the decibel meter at the same time in order to get accurate results. Another task I had to perform in order to complete my project was to measure the 11 relative positions and space them all out by one meter. I also had to go back into my recorder, stopwatch, and decibel meter, and gather all the data to put into my data table and graph.


3. What is new or novel about your project?

       a. Is there some aspect of your project's objective, or how you achieved it that you haven't done before?

       b. Is your project's objective, or the way you implemented it, different from anything you have seen?

       c. If you believe your work to be unique in some way, what research have you done to confirm that it is?

Something new about my project is that I tested the relative position instead of the spread or the sound. The way I tested the Doppler Effect was different from how people usually test it. I matched up all my measuring devices to get the most accurate results. I did research on sound relativity and the doppler effect in order to set up my experiment.


4. What was the most challenging part of completing your project?

      a. What problems did you encounter, and how did you overcome them?

      b. What did you learn from overcoming these problems?

The most challenging part of completing my project was matching up my stopwatch, sound recording device, and decibel meter. I learned that even though experiments can sometimes be hard, accurate results are what matters in the end.


5. If you were going to do this project again, are there any things you would you do differently the next time?

If I was to do this project again, since this one went as planned, I would probably test another variable. Some examples include speed and type of sound.


6. Did working on this project give you any ideas for other projects? 

Since I had so much fun with this experiment, I might do another experiment on sound. I was very interested in the topic of sound waves, so I might do something under that topic.


7. How did COVID-19 affect the completion of your project?

Fortunately, COVID-19 did not affect the completion of my project!