It's Hallowe'en; Get Your (Acoustical) Geek On!

If you’re not already watching it, I recommend CBS’ new comedy, The Big Bang Theory. I especially recommend it to anyone who falls, or has friends/family who fall, into the Geek/Nerd category.

This week’s episode was particularly hilarious as it had a Hallowe’en theme. One of the main characters, Sheldon, dressed up as the Doppler Effect. His costume was a centrally located circle representing a light source, with stripes representing waves of light at decreasing (or increasing, depending on the relative motion of the observer, of course) frequency eminating from the source. As an acoustician, I found this hilarious, especially when Sheldon was trying to explain his costume to other Hallowe’en party-goers: “You know;” [imitates a passing vehicle] “Nnyowm.” Fellow acousticians: How many times have you done that in your life?

This got me to thinking about other great acoustical Hallowe’en costumes:

• You could stand in place and bob up and down: You’re a Standing Wave. (To make it more obvious, you could simply stand in place and wave.)

• You could continually travel in a straight line from one side of the room to the other: You’re an Axial Room Mode. (You could get really creative if you wanted to be an Oblique Room Mode, but be careful not to break anything.) To enhance this costume, alternately raise and lower your voice to correspond to the appropriate sound pressure distribution.

• You could repeatedly repeat everything people say, lowering your voice with each repetition. You guessed it; you’re an Echo. This would be particularly effective if you only did it to the last syllable or three of any given sentence. Of course, with enough practice, you can simply repeat everything people say in a slightly lower voice.

• You could paint yourself and your clothes starting with red-orange around your mouth and moving through the ROYGBIV colors moving away from your mouth until your feet are violet/black: You’re a Spectrograph.

• You could get one of these for your head:

And one of these to wear around your neck:

And be a Sound Level Meter.

• Finally, not strictly acoustical, but you could get this printed on a T-shirt:

Then put a small loudspeaker in your pocket hooked up to a signal generator. Play a 1 kHz square wave through the loudspeaker and you can go around saying, “This is Only a Test.” People will love you.

Here are some more conceptual costumes you can ponder:

• Fast Fourier Transform (FFT)
• Helmholtz Resonator (Coke bottle, slat absorber, etc.)
• Signal-to-Noise Ratio (SNR)
• Sonar
• Ultrasound or a Sonogram
• Active Noise Control

Happy Hallowe’en!