# Labs: Part 1: Everyone does the same lab each week

• 1) Measurement and Errors:
Errors:Basic intro lab on errors and error analysis, sample measurements, scientific technique.

• 2) Transverse Waves
Vibrating Waves on a string.

• 3) Velocity of Sound in a Gas/Resonant Tubes
Measure speed of sound; provides a good model for instruments based on resonant air columns.

• 4) Speed of Sound:
Re-enactment of the famous experiment of Galileo's attempt to measure the speed of light. Yields crude measurement, but has historical significance, and teaches error analysis and background subtraction. Note, this must be done outdoors.

• 5) Simple musical instruments:
Using musical tuners, determine the frequency of the overtone series for a variety of simple instruments including different lengths of copper tube, a tubular reed recorder, and any other instrument the students care to try. Discuss harmonic, odd-harmonic series. Closed and open organ pipes.

• 6) Computer based lab:

• 1) Fourier Transforms:
Exercises using Mathematica (and other software if available) to experiment with Fourier Transforms. Generate and play sounds from a harmonic and odd-harmonic instrument.

• 2) Various exercises using the Experimental Acoustics CD produced by the American Acoustical Society.

• 3) Equal vs. Just Temperament. I have some sound samples comparing the two. Can also compute frequencies and plot each on log plot.

# Labs: Part 2: Everyone does a different lab each week

Note: For the following, there is only 1 equipment setup available, so the students must work in groups, and rotate each week.

• 1) Fourier Transforms:
Using a PC, we can compute FFT of various instruments, and analyze their harmonic fingerprint.

• 2) Diffraction and Interference, and refraction.
Use a wave-table to understand basic principles.

• 3) Diffraction and Interference, and refraction.
We have a set of speakers separated by 2m which can be used to measure interference of sound waves. Can vary frequency, and measure separation of nodes.

• 4) Resonant Flame tube:
Generate standing waves in a flame tube. Determine harmonics, and measure wavelength.

• 5) Oscilloscope experiments:

• 1) Lissajous Figures using 2 function generators

• 2) Lissajous Figures using mirrors and laser

• 3) Fourier synthesizer: build and hear complex waveforms

• 6) Standing wave patters in 2-Dimensions:
Use a mechanical wave driver to excite Chladni plates. Use square plates, and also shaped plates (i.e., violin shaped).

# Auxiliary material:

In addition to the material covered here, there is additional material covering the following topics in the UNT lab manual.

Vibration Modes

Loudness, Frequency, and Human Hearing

Reverberation Time

The Human Voice

Synthesizers, Computers, and MIDI