Measure speaker volume by recording playing sound with microphone

I want to measure a system's speaker volume by playing a sound and listening for it on a local microphone at the same time. This is for a specific application. The exact recorded sound is not as important as dif开发者_开发技巧ferentiating between the microphone volume recorded before the sound is played and while it is playing.

The idea is to warn the user if speakers are turned off or too low. How can I record a sound while playing it and determine a difference in volume? Are there are any managed libraries to do this?

Update: Found a good related question.

Take this:

http://windowsmedianet.sourceforge.net/

and use waveIn managed wrapper.

http://msdn.microsoft.com/en-us/library/ms712636(VS.85).aspx

Of course, you'll need some calibration there...