3C20.10 - Range of Hearing for the Human Ear

Code Number:
3C20.10
Demo Title:
Range of Hearing for the Human Ear
Condition:
Good
Principle:
Audible Frequency Range of the Human Ear
Area of Study:
Acoustics, Biology

Disclaimer

Equipment:
Wave generator, Amplifier, Speaker (large), Microphone, Tektronix 2235 oscilloscope, Stereo Preamp, Decibel Meter (Radio Shack), Frequency Meter (If Needed).
Procedure:

Video Credit: Jonathan M. Sullivan-Wood.

See also 3C20.10 in Chemistry and Physics of Everyday Experience.

Plug the generator into the auxiliary input of the amplifier and attach a speaker. Plug the microphone into the preamp and the preamp into the oscilloscope. Use the oscilloscope to show that there is sound produced in the inaudible range. The decibel meter may be used in place of the oscilloscope setup to show that there is still damaging levels of sound produced (Infrasound etc.) in the inaudible ranges.

References:
  • Lars-Jochen Thoms, Giuseppe Colicchia, and Raimund Girwidz, "Audiometric Test with a Smartphone", TPT, Vol. 56, #7, Oct. 2018, p. 478.
  • Richard P. McCall, "Earplugs and the NRR", TPT, Vol. 44, #9, Dec. 2006, p. 580.
  • Albert A. Bartlett, "Logarithmic Scales: A Useful Example", TPT, Vol. 41, #1, Jan. 2003, p. 16.
  • C.T. Tindle, "Decibels Made Easy", TPT, Vol. 34, #5, May 1996, p. 304.
  • Thomas D. Rossing, "Letters: 120 Decibels!", TPT, Vol. 27, #9, Dec. 1989, p. 644.
  • Thomas D. Rossing, "Letters: 106 Decibels!", TPT, Vol. 26, #5, May 1988, p. 264.
  • "How Physics Is Used to Repel Deer and Fleas", TPT, Vol. 24, #8, Nov. 1986, p. 503.
  • Robert Johns, "Musical String Vibrations", TPT, Vol. 15, #3, Mar. 1977, p. 145.
  • Hugh Haggerty, "Sound Intensity and Good Health", TPT, Vol. 12, #7, Oct. 1974, p. 421.
  • Sukhbir Mahajan, Michael Shea, D. L. Robinson, and Dave Mayhes, "Environmental Noise: An Undergraduate Research Project", AJP, Vol. 45, #10, Oct. 1977, p. 987.
  • C. V. Parise, K. Knorre, and M. O. Ernst, "Our Spatial Sense of Pitch", Physics Today, Vol. 67, #6, June 2014, p. 22.
  • Sh-3: Freier and Anderson, A Demonstration Handbook for Physics.
  • W-090: "Sound Level Mater", DICK and RAE Physics Demo Notebook.
  • W-085: "Oscillator and Oscilloscope", DICK and RAE Physics Demo Notebook.
  • W-055: "Hearing and Seeing Waves", DICK and RAE Physics Demo Notebook.
  • Pat Murphy, Ellen Macaulay, and the staff of the Exploratorium, "How High Can You Hear?" Exploratopia, p. 28.
  • Jearl Walker, "3.74, Infrasound", The Flying Circus of Physics Ed. 2, p. 175.
  • 1.45, Jearl Walker, "Getting Sick From Infrasound", The Flying Circus of Physics with Answers.
  • Ron Hipschman, "Hearing Range", Exploratorium Cookbook III, p. 193.1 - 193.4.
  • Tom Petruzzellis, "Sound Pressure", Electronic Sensors for the Evil Genius, p. 3.
  • Julius Sumner Miller, Q47 & A47, Millergrams I – Some Enchanting Questions for Enquiring Minds, p. 36 & 93.
http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/eqloud.html

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.