Beats with Sound

This mathlet generates tones from two sine waves. The frequencies of each sine wave can be set. If the frequencies are close together the combined sound exhibits the feature of "beats". The waveforms can also be displayed to show the corresponding visual feature of beats.

Graphs
The mathlet can display either or both sine waves and the mixed waveform which is the average of the two.

Buttons

Play/Stop: Play or stop the currently selected sound(s).

Checkboxes

Show: Show the associated waveform.
Play: Choose which waveforms play when the play button is pressed. If both waveforms are selected the resulting sound is the sum of the two sine waves.
Show envelope: Show the envelope for the mixed waveform.

Sliders

Frequency: Set the frequency of the associated waveform.
The little triangles at the end of each frequency slider can be used to fine tune the frequency. Clicking them increments the frequency by \(0.1\) hz. If you have a keyboard: shift-clicking increments the frequency by \(1.0\) hz and alt or option-clicking increments it by \(10\) hz.
Gain (DB): Add a gain to the associated waveform.
Zoom: Change the scale on the \(t\) (horizontal) axis.