Listen to keyboard without recording

I want to use Audacity as a simple mixer, so I can connect my Casio CTX-496 keyboard to my laptop and play along with online music lessons. I don’t want to record. (Audacity 2.0.5 & Windows 7 home premium). I am connecting my Casio headphonephone output directly to my laptop microphone input; then I would like to bring up online piano lessons a play along while hearing the output on my laptop’s headphones. I don’t need to record anything. Thanks for any suggestions - harry

That will probably give you distorted sound, but if you want to try, turn on Transport > Software Playthrough in Audacity, choose the mic input in Device Toolbar then click in the red recording meter in Meter Toolbar . Turn the input slider in Audacity Mixer Toolbar well down.

With the same quality warning, you don’t need to use Audacity at all. Right-click over the speaker icon by the system clock, then choose “Recording Devices”. Right-click over the mic then choose “Properties”. Then click the “Listen” tab, enable “Listen to this device” and choose the built-in headphones for playback.

Right-click over the mic and choose “Properties” again. Then click the “Levels” tab and turn the input level down.