Sound (MBL) Pre-lab Assignment

Your name: _____________________

Print this page, record your answers on it, and show it to your lab TF at the start of your lab session.

The philosophy behind the Sound experiment is a little different from other experiments in that we're strongly encouraging you to simply come to the lab and play with sound. In the lab you will record different sounds and analyze them, so you'll need sources of interesting sounds to investigate. Your voice is an excellent source, so be sure to bring that with you. We will provide some things you can examine but please bring one or more items of your own. Musical instruments (from kazoos to tubas) would be useful, but anything that produces an interesting sound should be fine.

What source or sources of sound will you bring with you to the lab?

The simulation that comes up when you press the button below generates sound. It's a good idea to turn the sound level down on your computer before running the simulation. There's also a mute box on the simulation itself. If your computer is not capable of producing sound, or if the sound generation part of the simulation does not work, no big deal - you can at least see a couple of different representations of the sound even if you can't hear it.

1. A good place to start is to press the buttons and see what you get. What does the Frequency Spectrum graph tell us about a particular sound wave?

2. Make some general comments on the differences between musical and non-musical sounds.

3. Beats - let's say you have a source sending out a 400 Hz sine wave. When you play a second source of sound simultaneously you hear a sound with a beat frequency of 8 Hz. What are the two possible frequencies of the second source of sound? Try editing the function in the simulation to test your answers.