Three Technologies Working Together
There are three technologies in the Alexa system that, when they work together, enable the device to recognize the wake word. Nothing else will begin the recording. These technologies are the microphones in the machine, a three-second memory buffer, and neural net training.
Microphones
The microphones also determine the direction the word comes from so they can focus in that direction. When the device determines the direction, a lighter blue color light will follow the sound of your voice.
Limited memory
The memory built into the Echo device only retains three seconds worth of data at a time. Then the data is erased and written over. For those of you old enough to remember cassette tapes, it would be like recording for three seconds and then rewinding to the beginning and recording for three seconds again. Alexa does not transmit data until after it recognizes the wake word.
Neural net training
Every word that Alexa hears runs through several layers of testing. This testing determines if the word is the wake word. After the word passes through several layers of verification, and the Echo device determines that it was indeed the wake word, Alexa begins recording.
Accuracy of wake word recognition
People worry that Alexa will begin recording without actually hearing the wake word. So it is vital that Alexa does not start recording without someone directly speaking to it. Recognizing the word and not getting it confused with other words is a top priority.
Erasing Stored Conversations
If you don’t want Alexa listening for the wake word, the simplest thing to do is to press the mute button on the top of the device. It won’t listen until you turn the microphones back on. You can change your settings to keep your data private. On the mobile app, open the settings and then select “Manage How Your Data Improves Alexa,” then toggle the switches to the off position. You can now even tell Alexa to forget everything you said that day. First, enable the skill by opening the settings, then Review Voice History. Turn the switch on. Then when you say, “Alexa, delete everything I said today,” the server deletes all the data from that day.
