Amazon’s Alexa loses her voice in this hilarious Superbowl ad featuring celebrities like Gordon Ramsay and Sir Anthony Hopkins. Amazon also has a clever trick to ensure your home’s Alexa won’t be activated during the ad, via Bloomberg:
The word “Alexa” is uttered 10 times during the Super Bowl spot, but thankfully, the Amazon Echo in your living room isn’t going to perk up and try to respond. An Amazon spokeswoman is guarded about explaining exactly why, saying only, “We do alter our Alexa advertisements … to minimize Echo devices falsely responding in customer’s homes.”
Bezos and company have evidently been thinking about this problem for a long time, before the Echo was even introduced. A September 2014 Amazon patent titled “Audible command filtering” describes techniques to prevent Alexa from waking up “as part of a broadcast watched by a large population (such as during a popular sporting event),” annoying customers and overloading Amazon’s servers with millions of simultaneous requests.
The patent broadly describes two techniques. The first calls for transmitting a snippet of a commercial to Echo devices before it airs. Then the Echo can compare live commands to the acoustic fingerprint of the snippet to determine whether the commands are authentic. The second tactic describes how a commercial itself could transmit an inaudible acoustic signal to tell Alexa to ignore its wake word.
About a year ago, a Reddit user calling himself Asphyhackr did a little more legwork and concluded that Amazon was creatively employing this second technique. By running Alexa commercials through digital audio editing software, Asphyhackr discovered that Alexa ads transmit weakened levels of sound in an upper portion of the audio spectrum, between 3,000 and 6,000 hertz, outside the most sensitive range of human hearing.