Decibel Production Due to Variation of Voltage

Chris Newberry

Table of Contents

Introduction| The Paper | Links| Bibliography| Back to Research Index                                                          

 

Introduction

Background Information:

    Two things which are associated with everyday life would be decibels and voltage.  A decibel is a unit used for expressing power ratios, sound-pressure ratios, and ratios of other quantities.  Voltage is electric potential energy per unit charge, measured in Joules per Coulomb.  The decibel is defined as a power relationship.

 

Review of Literature

    "To be a bit more specific, voltage is a way of using numbers to describe an electric field.  Electric fields are measured in voles over a distance.  A stronger electric field has more volts per centimeter than a weaker field.  Voltage and electric fields are basically the same thing: if electric fields are like the slope of a mountainside, than the volts are like the various heights of each different spot on the mountain" (Beaty).  "Sound waves are introduced into a medium by the vibration of an object" (Henderson). 

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The Paper

Question| Hypothesis| Materials| Procedure| Data| Conclusion

 

Question:

Does voltage affect the amount of decibels produced by a Piezo Buzzer?

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Hypothesis:

If I increase the amount of voltage going through a small buzzer then the decibels will increase because more voltage means less current going to the buzzer which would increase the decibels.   

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Materials:

Small Piezo Buzzer

30cm long acrylic tube, 3.8 cm diameter

Board to mount buzzer and tube

Duct tape

Decibel meter

Power Supply

Multimeter or Voltmeter

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Procedure:

  1. Secure acrylic tube to board, use the “amazing” duct tape
  2. Secure buzzer in end of tube that is fully on the board, make sure the buzzer microphone is facing down the long end of the tube
  3. Using alligator clips, connect the buzzer, voltmeter, and power supply
  4. Plug in power supply
  5. Position decibel meter in a secure place where it won’t move, I kept the dB microphone 8.5cm from the end of the tube
  6. Turn on power supply and increase voltage until it hits 1V.  Once 1V is acquired, record the amount of decibels produced.  Turn off power supply and wait for all buzzing to completely vanish
  7. Repeat step 6 for 1.5V, 2.0V, 2.5V, 3.0V, 4.0V, 5.0V, 6.0V, 7.0V, and 8.0V
  8. Repeat steps 6 and 7 for two more trials.  RECORD ALL DATA

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Paint Picture

 

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Data:

After completing all my trials I put them into a table, as seen below.

 

Data File (Text Tab Delimited)

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Conclusion:

My results support my hypothesis, but they do show some inconsistencies.  I thought I would have had higher decibels as the voltage increased all the way to eight, but it seemed to reach a maximum at four or five volts.  The pitch did increase all the way through eight volts, which is why I stopped testing at eight volts.  A maximum decibel level may have been reached because the buzzer started its best readings at those voltages.  Some problems I may have run into could be: unstable noise conditions, uncertainties of up to +/- .02 Volts, or small glitches with equipment.  All these factors may have given some slight alterations to my project.  If I were to do this again I would try to pick a quieter environment and do even more trials and voltage levels.

 

 

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Links

http://arts.ucsc.edu/EMS/Music/tech_background/TE-06/teces_06.html- Background information on sound, music, and decibels. 

 

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elevol.html- Gives basic information into the way voltage works.

 

 http://amasci.com/miscon/voltage.html- "What is Voltage?", This website gives more information into voltage and Electric Fields.

 

http://ourworld.compuserve.com/homepages/g_knott/elect347.htm- BELS, DECIBELS AND dB

 

http://www.mcsquared.com/dbframe.htm-  This calculation will give you the amount of attenuation, in decibels, you can expect with a change in receiver distance.

 

 

 

 

Bibliography

1. Lurch, E. Norman “Decibel.” Encyclopedia Americana. 2007. Grolier Online. 13 Nov. 2007

            http://ea.grolier.com/cgi-bing/article?assetid=0121770-00

 

2. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elevol.html

 

3. “WHAT IS VOLTAGE” 1998, William J. Beaty

            http://amasci.com/miscon/voltage.html

 

4. “Intensity and the Decibel Scale” Tom Henderson, 1996-2007

            http://www.glenbrrok.k12.il.us/gbssci/Phys/Class/sound/u11l2b.html

 

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