Measure Tones, Vowels and Telephones
The complete experiment can be found in the Physics With Vernier book, experiment 34.
In this experiment, you will analyze various common sounds. You will use a Microphone connected to a computer. The data-collection program will display the waveform of each sound, and will perform a Fast Fourier Transform (or FFT) of the waveform. The FFT tells you the amplitudes and frequencies of a collection of sine waves that, when added together, would sound the same as the original waveform.
In the first part of the experiment, you will study the sound of a tuning fork, which produces a tone composed mainly of a single frequency. Next, you will observe the production of overtones on a tuning fork. Overtones whose frequencies are multiples of the fundamental are called harmonic; other overtones are called inharmonic. You will also analyze the sound produced when you say two vowels.
In the last part of the experiment, you will be given a problem to solve. How does the telephone company know what numbers you dial?
- Use a Microphone to analyse the frequency components of a tuning fork and your voice.
- Record overtones produced with a tuning fork.
- Examine how a touch-tone phone works.
Sensors and Equipment
Option 2 (Less Accurate)
You may also need an interface and software for data collection.