Speed of Sound

   It is possible to determine the speed of sound through a relatively simple experiment.  The experiment will use a speaker and a microphone.  For simplicity a sound card will be used to both acquire the data and control the speaker.

Theory

To measure the speed of sound it requires the ability to control, or find out, when a sound starts and compare that to when a sound is heard.   

 

(((( Initial testing confirms that this experiment may not be possible using a standard sound card.  I have performed

this experiment using a PCI-MIO-16E-4 card and a function generator generating an AM modulated wave with a carrier of around 25kHz.    )))

Equipment Used

Standard amplified computer speaker.

Standard computer microphone.

Computer with a standard sound card and Labview

A tape measure or other measurement tool.

Equipment Setup

  1. Connect the amplified speaker to the output of the computer sound card.

  2. Connect the microphone to the microphone input of the sound card.

  3. Position the speaker inline with the microphone about a third of a meter away.

Program (VI) Construction

(((vi in progress on my home computer)))

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 a erfrequency response for many simple circuits using nothing more than a sound card and Labview.  This lab illustrates a practical example of this.

    Ultimately all a sound card can do is sample a signal at a set frequency and play a different signal back.  To simplify out analysis we shall set both the recording and the playback frequency at 44.1kHz and base our analysis on this.