Tips for Choosing a Wake Word

  • Hotword
  • Phonemes
  • Trigger word
  • Wake up word
May 31, 2019

A wake word is a special word or phrase that is meant to activate a device when spoken. It is also referred to as 'hotword', 'trigger word', and 'wake up word'. There are a few famous wake phrases such as "Hey Siri", "OK Google", and "Alexa".

A wake word should be unique and promote the brand of the device or application using it. A good choice of wake word can also substantially increase the accuracy of the voice interface it is enabling. Below are guidelines we gathered through numerous interactions with clients onboarding Picovoice's wake word engine.

Avoid Short Single-Word Phrases

Detecting short phrases is difficult for both humans and machines, especially in presence of noise and echo. Most well-known wake words have at least six phonemes: "OK Google" has eight phonemes and "Alexa" has six. Choosing a wake phrase with fewer than six phonemes is not recommended, because it is harder to detect and more likely to produce false positives. A short wake word can can be made more effective by prepending it with "Hey", "OK", etc.

Avoid Long Phrases

There is a trend to use shorter wake phrases. For example, Amazon has only single-word wake phrases and Google moved from "Ok Google Now" to "Ok Google". Long and multi-word wake phrases are cumbersome and can result in a poor user experience.

Choose Words with Diverse Sounds

Pick a phrase that has a variety of different sounds. A simple test for this property is to count the number of syllables in the wake phrase. For example, Alexa and Cortana both have three syllables. Choosing a wake phrase that has fewer than three syllables is not recommended. If your wake phrase has fewer than three syllables, can prepend it with "OK", "Hey", etc. For example "Google" has two syllables but "OK Google" has four.