I have the microphone enabled in the duolingo settings and I know I have a microphone in my computer (I have a macbook)- I checked the settings under google chrome voice commands and it seems to be configured ok. I don't think the little 'adobe flash player' box has ever popped up for me during the set up. I have a macbook (about 1.5 years old), use google chrome, and popups, cookies & javascript are all enabled in my google chrome settings. Thanks!