Users' Guide User guide

Xplorer GLX Users’ Guide 137

Activity 10:Beat Frequency

Background

When two sound waves with slightly different frequencies combine, the pattern

of interference produced is known as beats. The rate at which the beats occur is

the beat frequency.

In this activity, the GLX will generate two tones whose frequencies differ by ∆ f,

and you will hear the resulting beats. By varying the frequency of one of the

tones, you will discover the relationship between ∆ f and beat frequency.

Before You Begin

Start a new experiment on the GLX.

1. Press to go to the Home Screen.

2. Use the arrow keys to highlight the Data Files icon and press to open

the Data Files screen.

3. Press to open the Files menu and press to select New File.

4. When the GLX asks if you would like to save the previous file, press

to save or not to save.

Procedure

GLX Set-Up

1. Press to return to the Home Screen.

2. Use the arrow keys to highlight the Output icon and press .

3. If the Speaker Configuration is not already set to Mono, use the arrow keys

to highlight Speaker Configuration and press to set it to Mono.

4. Use the arrow keys to highlight the Frequency of the Left Output Channel

(as pictured to the right) and press to increase the Frequency to 441 Hz.

5. Press to open the Left Step Size menu. Press the up arrow key to high-

light Step 0.1, then press .

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