Sound on Lenovo laptop with win 8.1 fine until I start Audacity. Then the left channel quits. Even if I quit Audacity, the left channel is dead until reboot.
What are you listening to?
This is a 39 second Left and Right sound test. My voice bounces back and forth and I announce where I am.
See if it plays OK with and without Audacity and remember where it fails.
Your test works until Audacity is started. Then the left channel cuts out. There is no other channel problem on the laptop.
Are you using the latest Audacity 2.1.2? See the pink panel at the top of the page.
Has Audacity always done this? It could be an audio driver problem. Have you been to Lenovo’s site and installed or reinstalled the audio drivers for your particular computer model? If you have 64-bit Windows 8.1, be sure to install the 64-bit audio drivers.
Note that when launching, recent Audacity versions including 2.1.2 will reset the sound balance to centre, if the balance was otherwise. So that also makes me think your audio drivers are suspect.