Voices — Hume API

The Empathic Voice Interface (EVI) can be configured with any of our 8 base voices. You can also customize these voices by adjusting specific attributes. This guide explains each attribute and provides a tutorial for creating a custom voice. Visit the Playground to test the base voices.

The custom voices feature is experimental and under active development. Regular updates will focus on improving stability and expanding attribute options.

Voice attributes

The following attributes can be modified to personalize any of the base voices:

Attribute	Description
Gender	The vocalization of gender, ranging between more masculine and more feminine.
Articulation	The clarity of the voice, ranging between mumbled and articulate.
Assertiveness	The firmness of the voice, ranging between whiny and bold.
Buoyancy	The density of the voice, ranging between deflated and buoyant.
Confidence	The assuredness of the voice, ranging between shy and confident.
Enthusiasm	The excitement within the voice, ranging between calm and enthusiastic.
Nasality	The openness of the voice, ranging between clear and nasal.
Relaxedness	The stress within the voice, ranging between tense and relaxed.
Smoothness	The texture of the voice, ranging between smooth and staccato.
Tepidity	The liveliness behind the voice, ranging between tepid and vigorous.
Tightness	The containment of the voice, ranging between tight and breathy.

Each voice attribute can be adjusted relative to the base voice’s characteristics. Values range from -100 to 100, with 0 as the default. Setting all attributes to their default values will keep the base voice unchanged.

Crafting custom voices

See instructions below for customizing a voice through the Portal.

Navigate to the Voices page

In the Portal, find the EVI Voices page. Click the Create voice button to begin.

Navigating to the voices page, step 1 of EVI custom voice creation

Create a new custom voice

Enter a name for your custom voice and select a base voice. Then, adjust the attributes.

Create voice menu with voice attribute options, step 2 of EVI custom voice creation

Test your custom voice

As you make tweaks to the attributes, sample audio can be generated by clicking the ”▶” button in the Voice sample section at the bottom of the form.

Testing a custom voice with audio playback, step 3 of EVI custom voice creation

Use your custom voice

The newly created voice can now be deployed. From the Voices page, click Use to create an EVI configuration with it.

Accessing a custom voice for use with an EVI, step 4 of EVI custom voice creation — Successful voice creation

When creating an EVI configuration, choose Custom voice and press the + Select button. Then, press Select existing custom voice… and confirm the custom voice you would like to use.

Selecting a custom voice in an EVI configuration