If your wake word isn’t unique, then there’s a greater chance of your assistant ‘waking up’ when it’s not intended to be invoked. This is known as false acceptance. The opposite effect, a false positive, happens when your voice assistant is unresponsive to your wake word.

2. Make sure your wake word is not too long

There isn’t a specific, maximum limit for the length of a wake word, technically. However, if your wake word is too long, you risk some pretty severe user experience limitations. 

People don’t have great short-term memories. If your wake word is too long, then there’s a good chance that people won’t remember it. Either that, or it takes a heavy cognitive effort to remember your wake word. Both of which aren’t great user experiences. 

The optimum length for a wake word is between four to five syllables. It’s typically best practice to have at least three syllables to give the voice assistant enough of a pattern to recognize accurately.

Insider knowledge: This is why the Google Assistant wake word is “Hey Google” or “OK Google”: it’s three syllables.

3. Don’t have too many similar sounds 

Your wake word should have some variation in the sounds it contains within it and shouldn’t have too many similar sounds. For example, if Santa created a voice assistant, then a wake word of “Ho, ho, ho” contains too many concurrent “ho” sounds for it to be an effective wake word. “Hey Santa” would work much better.

“You really want some phonetic variation in the phrase and lots of differentiation between consonants and vowels in order to really create a different sound than other words or phrases in the language. You don’t want a lot of the same sounds repeated,” according to Darin.

There’s a way we can actually look at specific wake phrases and determine if it doesn’t have enough phonetic variation, if it has a lot of phonetic variation, and if it’s too similar to other phrases that are pretty common in the language. We can then make a recommendation for usage based on all these findings,” he said.

4. Make your wake word easy to differentiate

To eliminate accidental wake-ups—or instances where the voice assistant is not responsive to user queries—it’s important to differentiate your wake word from common words, names, and even the name of your company.

There are a number of ways to ensure your wake word doesn’t suffer from a lot of false acceptances or false rejections and to differentiate it from normal conversation. 

Here are the top 3 ways to differentiate your wake phrase:

1. Differentiating between the device

Your wake word should be different from the name of the device that it runs on. For example, having the wake word “Echo” runs the risk of the assistant being activated when someone is discussing the device in normal conversation. Although Amazon allows you to set its wake word to “Echo”, those that do will notice the device wake-up when your friend asks “Do you have an Echo?”

2. Differentiating between the company

If your company name is Delany and your wake word is “Delany”, then you’re again going to generate a lot of false acceptances. Your assistant will wake up when it’s not intended to be invoked more often.

This is why brands like Pandora and Hyundai add words like “Hey”, “OK”, or “Hello” before their brand names in their wake phrases. “Hey Pandora” is enough to differentiate the wake word from somebody just talking about the music streaming service during a normal conversation.

3. Differentiating between natural conversation

We’ve all had the experience of having our Echo devices wake up during the course of a natural conversation. It must be a nightmare having an Echo if your actual name is Alexa. 

If you decide you want to give your product a name, instead of having your users use the company or product name, you’ll need to think through all the connotations that name may have for people. In addition, if the name is too common, it may spark those false positives you’re trying to avoid. Choose a gender-neutral name that is not shared by real people and ideally one that’s an extension of your brand.

A good wake word includes a combination of sounds that are pleasing, but not easily rhymed and easily distinguishable from language or sounds made during the course of a natural conversation. 

4. Make your wake word work across borders

Many companies have customers and users across borders, and if you don’t have international customers today, maybe you will tomorrow. Even if your customers are all located in North America, their native language may not be English. In addition to speaking an array of languages, people in various geographical areas may speak the same language with a variety of accents.