Echo by Amazon

Source: Youtube Amazon

Amazon Echo - Official site - Request an invitation

Tucked under Echo's light ring is an array of seven microphones. These sensors use beam-forming technology to hear you from any direction. With enhanced noise cancellation, Echo can hear you ask a question even while it's playing music. Echo uses on-device keyword spotting to detect the wake word.

http://www.amazon.com/oc/echo/ref_=ods_dp_ae