Klatt Voice Synthesis

The Klatt Voice Synthesis system provides custom text-to-speech for GS_Play projects using Klatt formant synthesis with full 3D spatial audio. It uses SoLoud internally for speech generation and MiniAudio for spatial positioning.

The system has two layers:

• KlattVoiceSystemComponent – A singleton that manages the shared SoLoud engine instance and tracks the 3D audio listener position.
• KlattVoiceComponent – A per-entity component that generates speech, queues segments, applies voice profiles, and emits spatialized audio from the entity’s position.

Voice characteristics are defined through KlattVoiceProfile assets containing frequency, speed, waveform, formant, and phoneme mapping configuration. Phoneme maps convert input text to ARPABET phonemes for the Klatt synthesizer, with support for custom pronunciation overrides.

For usage guides and setup examples, see The Basics: GS_Audio.

Contents

• Components
• API Reference
• Data Types
• Enumerations
• KTT Voice Tags
• Combined Example
• See Also

Components

KlattVoiceSystemComponent

Singleton component that manages the shared SoLoud engine and 3D listener tracking.

KlattVoiceComponent

Per-entity voice component with spatial audio, phoneme mapping, and segment queue.

API Reference

Request Bus: KlattVoiceSystemRequestBus

System-level voice management. Singleton bus – Single address, single handler.

Request Bus: KlattVoiceRequestBus

Per-entity voice synthesis controls. Entity-addressed bus – Single handler per entity ID.

Notification Bus: KlattVoiceNotificationBus

Events broadcast by voice components. Multiple handler bus – any number of components can subscribe.

Data Types

KlattVoiceParams

Core voice synthesis parameters controlling the Klatt formant synthesizer output.

KlattVoiceProfile

A voice profile asset combining synthesis parameters with a phoneme mapping.

KlattVoicePreset

A preset configuration for quick voice setup.

KlattSpatialConfig

3D spatial audio configuration for voice positioning.

KlattPhonemeMap

Phoneme mapping asset for text-to-ARPABET conversion with custom overrides.

PhonemeOverride

A custom pronunciation rule that overrides the base phoneme map for a specific word or pattern.

Enumerations

KlattWaveform

Glottal waveform types available for the Klatt synthesizer.

BasePhonemeMap

Available base phoneme dictionaries for text-to-ARPABET conversion.

KTT Voice Tags

KTT (Klatt Text Tags) are inline commands embedded in strings passed to KlattVoiceComponent::SpeakText. They are parsed by KlattCommandParser::Parse and stripped from the spoken text before synthesis begins — they are never heard.

Format: <ktt attr1=value1 attr2=value2>

Multiple attributes can be combined in a single tag. Attribute names are case-insensitive. String values may optionally be wrapped in quotes. An empty value (e.g. speed=) resets that parameter to the voice profile default.

speed=X

Override the speech speed multiplier from this point forward.

Normal speech <ktt speed=2.0> fast bit <ktt speed=> back to default.

decl=X / declination=X

Pitch declination — how much pitch falls over the course of the utterance. Both decl and declination are accepted.

Rising <ktt decl=0.0> steady <ktt decl=0.8> falling voice.

waveform="TYPE"

Change the glottal waveform used by the synthesizer, setting the overall character of the voice.

<ktt waveform="noise"> whispered section <ktt waveform="saw"> normal voice.

vowel=X

First formant (F1) frequency multiplier. Shifts the quality of synthesised vowel sounds.

<ktt vowel=1.4> different vowel colour here.

accent=X

Second formant (F2) frequency multiplier. Shifts accent or dialect colouration.

<ktt accent=0.8> shifted accent here.

pitch=X

F0 pitch variance amount. Controls how much pitch varies during synthesis.

<ktt pitch=2.0> very expressive speech <ktt pitch=0.1> flat monotone.

pause=X

Insert a pause of X seconds at this position in the voice playback. Value is required — there is no default.

Hello.<ktt pause=0.8> How are you?

Combined Example

Dialogue string using typewriter text commands and KTT voice tags together:

[b]Warning:[/b] [color=#FF0000]do not[/color] proceed.[pause=1]
<ktt waveform="square" pitch=1.8>This is a mechanical override.<ktt pause=0.5><ktt waveform="saw" pitch=1.0>
[speed=3]Resuming normal protocol.[/speed]

See Also

For conceptual overviews and usage guides:

• GS_Audio Overview – Top-level audio gem documentation
• The Basics: GS_Audio – Scripting-level usage guide

For component references:

• Audio Manager – Manager lifecycle that the voice system participates in

Get GS_Audio

GS_Audio — Explore this gem on the product page and add it to your project.