From Scott Snyder at the IU following our tech meetings.

“We heard from a number of your staff about a sound issue involving Lenovo laptops; many mentioned ThinkPads. In trying to track this down, here is what I found:

Try looking at this audio setting found in this article:

One more specific reference to that feedback loop message was found on a Lenovo site and referenced uninstalling SmartAudio 3 to fix the problem. Here are two threads addressing the issue: Thread one   Thread two