Let's be fair, the product is designed to specifically not do that:
"Echo uses on-device keyword spotting to detect the wake word. When Echo detects the wake word, it lights up and streams audio to the cloud, where we leverage the Alexa Voice Service to recognize and respond to your request."
"Echo uses on-device keyword spotting to detect the wake word. When Echo detects the wake word, it lights up and streams audio to the cloud, where we leverage the Alexa Voice Service to recognize and respond to your request."