Amazon Introduces the Echo

Amazon introduced the first Echo smart speaker in late 2014 as an invitation-only product. Its defining feature was Alexa, a voice assistant designed to be available from across a room rather than only after pressing a button on a phone.

The Echo used an array of microphones and beamforming techniques to isolate speech from background noise and determine where a voice was coming from. A wake-word detector listened locally for “Alexa,” while most speech recognition and language processing happened in Amazon’s cloud.

The device created a new application model through Alexa Skills, allowing third parties to expose services through voice commands. It also raised lasting privacy questions because an always-listening microphone had become a normal household computer interface.