The Elements of Voice First Style

Chapter 18. On Silence

Silence for VUI design is what the number zero is for algebra. As a concept and a tool, it is at the same time essential, ubiquitous, and taken for granted.

In this chapter, we highlight the main cases where the use of silences and pauses can contribute to a smoother, more usable voice user experience.

Here’s a brief interaction between a stock management voicebot and a human user:

VOICEBOT: Here’s what you can do: get quotes, buy stock, or sell stock. You can also say, “Speak to a manager.”

USER: Get quotes.

VOICEBOT: Getting quotes. As of 10:25 a.m., IBM is trading at eighty-two dollars and thirty-five cents, Apple at one hundred three dollars and twenty-four cents, and Google at three hundred seventy-four dollars and thirteen cents.

Let’s pinpoint where silences can enhance the usability of the user’s experience.

Prior to Listing Options

When the voicebot is about to provide the user with a list of options, a brief, half-second pause should be inserted between the announcement prompt and the first option that is played to the listener:

VOICEBOT: Here’s what you can do:

[silence]

get quotes, buy stock, or sell stock. You can also say,

[silence]

“Speak to a manager.”

Be careful with the language that precedes the enumeration of the options lest the language triggers the user to speak too soon. For instance, if the voicebot were to say, “What can I help you with?” and then pause, the user may start speaking, since that is a full request in its own right. ...