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

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

See also 3C20.10 in Oscillations/Acoustics

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:
  • 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, p.  16 Jan. 2003.
  • C.T. Tindle, "Decibels Made Easy", TPT, Vol. 34, # 5, May 1996, p. 304.
  • Thomas D. Rossing,  "Letters: 120 Decibels!",  TPT, Vol. 27, # 9, p.  644, December 1989.
  • Thomas D. Rossing,  "Letters: 106 Decibels!",  TPT, Vol. 26, # 5, p.  264, May 1988.
  • "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.
  • Sh- 3:  Freier and Anderson,  A Demonstration Handbook for Physics.
  • W- 055:  "Hearing and Seeing Waves",  DICK and RAE Physics Demo Notebook.
  • W- 085:  "Oscillator and Oscilloscope",  DICK and RAE Physics Demo Notebook.
  • W- 090:  "Sound Level Mater",  DICK and RAE Physics Demo Notebook.
  • C. V. Parise, K. Knorre, M. O. Ernst, "Our Spatial Sense of Pitch", Physics Today, June 2014, p. 22.
  • 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.

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