My Echo Dot is placed on my desk right next to my computer and monitor. The linear distance between me and the Dot is about 3 feet.
For the past week, I've been sick with a cold and coughing frequently. When I cough, especially when it's a loud cough, the Dot's blue ring lights up thinking I said Alexa. It's quite funny. But of course, Dot realized that I didn't actually say Alexa so it just ignores me. Still interesting nonetheless.