3B30.40 - Speaker and Candle Flame

Code Number:
Demo Title:
Speaker and Candle Flame
Pressure Waves
Area of Study:
Large Open Speaker, Candle, Grill Lighter, and Wave Generator.

Place a lit candle in front of a speaker. Adjust the generator from 0 to 150 Hz while observing the candle flame. You may need to move the candle/speaker distance to find the optimum position.

  • Cameron T. Vongsawad, Mark L. Berardi, Tracianne B. Neilsen, Kent L. Gee, Jennifer K. Whiting, and M. Jeannette Lawler, "Acoustics for the Deaf: Can You See Me Now?", TPT, Vol. 54, #6, Sept. 2016, p. 369.
  • P. Simeão Carvalho, E. Briosa, M. Rodrigues, C. Pereira, and M. Ataíde, "How to Use a Candle to Study Sound Waves", TPT, Vol. 51, #7, Oct. 2013, p. 398.
  • Zdeslav Hrepic, Corey Nettles, and Chelsea Bonilla, "Demonstrating Sound Wave Propagation with Candle Flame and Loudspeaker", TPT, Vol. 51, #1, Jan. 2013, p. 16.
  • Curt Suplee, "Blown Away", Everyday Science Explained, National Geographic, p. 58 - 59.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.