Voice

Configure text-to-speech voices for your agent.

Overview

AI Dev Kit supports voices from:

OpenAI - 6 voices (alloy, echo, fable, onyx, nova, shimmer)
ElevenLabs - Custom voices and voice library
Google - Neural2 and WaveNet voices
Azure - Neural voices

OpenAI Voices

Available Voices

public enum OpenAIVoice
{
    Alloy,    // Neutral, balanced
    Echo,     // Male, clear
    Fable,    // British accent
    Onyx,     // Deep male
    Nova,     // Female, friendly
    Shimmer   // Female, warm
}

Set Voice

// In AgentSettings
settings.OutputAudioParameters.Voice = "nova";

// At runtime
agent.Voice = new Voice("nova");

Try All Voices

public class VoicePreview : MonoBehaviour
{
    [SerializeField] private AgentBehaviour agent;
    
    private string[] voices = { "alloy", "echo", "fable", "onyx", "nova", "shimmer" };
    
    public async void PreviewVoice(int index)
    {
        string voice = voices[index];
        agent.Voice = new Voice(voice);
        
        AudioClip clip = await agent.GenerateSpeechAsync(
            $"Hello, I am {voice}. This is how I sound."
        );
        
        agent.OutputAudioPlayer.Play(clip);
    }
}

Voice Characteristics

OpenAI Voice Guide

public class VoiceCharacteristics
{
    public static string GetDescription(string voice)
    {
        return voice switch
        {
            "alloy" => "Neutral, balanced tone. Good for general use.",
            "echo" => "Male voice, clear and direct. Professional.",
            "fable" => "British accent, expressive. Storytelling.",
            "onyx" => "Deep male voice. Authoritative.",
            "nova" => "Female, friendly and conversational.",
            "shimmer" => "Female, warm and soothing.",
            _ => "Unknown voice"
        };
    }
}

Choose by Use Case

public Voice GetVoiceForUseCase(string useCase)
{
    return useCase switch
    {
        "assistant" => new Voice("nova"),      // Friendly helper
        "tutorial" => new Voice("alloy"),      // Clear instructor
        "narrator" => new Voice("fable"),      // Storyteller
        "character" => new Voice("onyx"),      // Deep character
        "guide" => new Voice("echo"),          // Professional guide
        _ => new Voice("alloy")
    };
}

Voice Settings

Speech Parameters

// In AgentSettings.OutputAudioParameters
settings.OutputAudioParameters = new SpeechParameters
{
    Model = "tts-1-hd",        // or "tts-1" for standard
    Voice = "nova",
    Speed = 1.0f,              // 0.25 to 4.0
    Format = AudioFormat.mp3    // or wav, opus, etc.
};

Speed Control

// Normal speed
agent.Settings.OutputAudioParameters.Speed = 1.0f;

// Slower (better for learning)
agent.Settings.OutputAudioParameters.Speed = 0.8f;

// Faster (efficient)
agent.Settings.OutputAudioParameters.Speed = 1.25f;

// Very slow
agent.Settings.OutputAudioParameters.Speed = 0.5f;

// Very fast
agent.Settings.OutputAudioParameters.Speed = 2.0f;

Runtime Speed Adjustment

public class SpeedControl : MonoBehaviour
{
    [SerializeField] private AgentBehaviour agent;
    [SerializeField] private Slider speedSlider;
    
    void Start()
    {
        speedSlider.minValue = 0.5f;
        speedSlider.maxValue = 2.0f;
        speedSlider.value = 1.0f;
        
        speedSlider.onValueChanged.AddListener(OnSpeedChanged);
    }
    
    void OnSpeedChanged(float speed)
    {
        agent.Settings.OutputAudioParameters.Speed = speed;
        Debug.Log($"Speech speed: {speed:F2}x");
    }
}

Voice Selection UI

public class VoiceSelector : MonoBehaviour
{
    [SerializeField] private AgentBehaviour agent;
    [SerializeField] private TMP_Dropdown voiceDropdown;
    
    private string[] voices = { "alloy", "echo", "fable", "onyx", "nova", "shimmer" };
    
    void Start()
    {
        // Populate dropdown
        voiceDropdown.ClearOptions();
        voiceDropdown.AddOptions(voices.ToList());
        
        // Set current selection
        int currentIndex = Array.IndexOf(voices, agent.Voice.Id);
        voiceDropdown.value = currentIndex;
        
        // Listen for changes
        voiceDropdown.onValueChanged.AddListener(OnVoiceChanged);
    }
    
    void OnVoiceChanged(int index)
    {
        string voice = voices[index];
        agent.Voice = new Voice(voice);
        
        Debug.Log($"Voice changed to: {voice}");
        
        // Save preference
        PlayerPrefs.SetString("PreferredVoice", voice);
    }
}

Voice Preview Buttons

public class VoicePreviewUI : MonoBehaviour
{
    [SerializeField] private AgentBehaviour agent;
    [SerializeField] private VoiceButton[] voiceButtons;
    
    void Start()
    {
        foreach (var button in voiceButtons)
        {
            button.onClick.AddListener(() => PreviewVoice(button.voiceName));
        }
    }
    
    async void PreviewVoice(string voiceName)
    {
        // Temporarily set voice
        var originalVoice = agent.Voice;
        agent.Voice = new Voice(voiceName);
        
        // Generate preview
        AudioClip clip = await agent.GenerateSpeechAsync(
            $"Hello, I'm {voiceName}. Nice to meet you!"
        );
        
        // Play
        agent.OutputAudioPlayer.Play(clip);
        
        // Wait for playback
        await UniTask.Delay((int)(clip.length * 1000));
        
        // Restore original voice
        agent.Voice = originalVoice;
    }
}

Character Voices

Assign Voices to Characters

public class CharacterVoiceManager : MonoBehaviour
{
    [System.Serializable]
    public class Character
    {
        public string Name;
        public string Voice;
        public float Speed;
    }
    
    [SerializeField] private AgentBehaviour agent;
    [SerializeField] private Character[] characters = new[]
    {
        new Character { Name = "Hero", Voice = "onyx", Speed = 1.0f },
        new Character { Name = "Guide", Voice = "nova", Speed = 0.9f },
        new Character { Name = "Narrator", Voice = "fable", Speed = 0.8f }
    };
    
    public async UniTask SpeakAs(string characterName, string text)
    {
        var character = characters.FirstOrDefault(c => c.Name == characterName);
        if (character == null)
        {
            Debug.LogWarning($"Character not found: {characterName}");
            return;
        }
        
        // Set voice and speed
        agent.Voice = new Voice(character.Voice);
        agent.Settings.OutputAudioParameters.Speed = character.Speed;
        
        // Generate speech
        AudioClip clip = await agent.GenerateSpeechAsync(text);
        agent.OutputAudioPlayer.Play(clip);
    }
}

ElevenLabs Integration

Custom Voices

// Set ElevenLabs voice (if using ElevenLabs provider)
agent.Settings.AudioProvider = AudioProvider.ElevenLabs;
agent.Voice = new Voice("voice_id_from_elevenlabs");

// With custom settings
agent.Settings.OutputAudioParameters = new SpeechParameters
{
    Voice = "your_voice_id",
    Stability = 0.5f,      // 0-1
    SimilarityBoost = 0.75f // 0-1
};

Voice Cloning

// Clone voice from samples (ElevenLabs API)
public async UniTask<string> CloneVoice(AudioClip[] samples, string name)
{
    // Upload samples to ElevenLabs
    // Returns voice_id
    
    string voiceId = await ElevenLabsAPI.CloneVoiceAsync(samples, name);
    
    // Use cloned voice
    agent.Voice = new Voice(voiceId);
    
    return voiceId;
}

Voice Persistence

Save User Preference

void Start()
{
    // Load saved voice
    string savedVoice = PlayerPrefs.GetString("PreferredVoice", "alloy");
    agent.Voice = new Voice(savedVoice);
    
    Debug.Log($"Using voice: {savedVoice}");
}

public void SetVoice(string voiceName)
{
    agent.Voice = new Voice(voiceName);
    
    // Save preference
    PlayerPrefs.SetString("PreferredVoice", voiceName);
    PlayerPrefs.Save();
    
    Debug.Log($"Voice saved: {voiceName}");
}

Per-Agent Voices

public class MultiAgentVoices : MonoBehaviour
{
    [SerializeField] private AgentBehaviour assistantAgent;
    [SerializeField] private AgentBehaviour tutorAgent;
    [SerializeField] private AgentBehaviour narratorAgent;
    
    void Start()
    {
        // Each agent has different voice
        assistantAgent.Voice = new Voice("nova");
        tutorAgent.Voice = new Voice("echo");
        narratorAgent.Voice = new Voice("fable");
    }
}

Voice Quality

Model Selection

// High quality (slower, more expensive)
agent.Settings.OutputAudioParameters.Model = "tts-1-hd";

// Standard quality (faster, cheaper)
agent.Settings.OutputAudioParameters.Model = "tts-1";

Audio Format

// MP3 (compressed, smaller files)
agent.Settings.OutputAudioParameters.Format = AudioFormat.mp3;

// WAV (uncompressed, high quality)
agent.Settings.OutputAudioParameters.Format = AudioFormat.wav;

// Opus (web optimized)
agent.Settings.OutputAudioParameters.Format = AudioFormat.opus;

Best Practices

1. Test Voices for Your Use Case

public class VoiceTester : MonoBehaviour
{
    [SerializeField] private AgentBehaviour agent;
    
    private string testPhrase = "Welcome to the game. Let me guide you through the tutorial.";
    
    public async void TestAllVoices()
    {
        string[] voices = { "alloy", "echo", "fable", "onyx", "nova", "shimmer" };
        
        foreach (string voice in voices)
        {
            agent.Voice = new Voice(voice);
            
            Debug.Log($"Testing voice: {voice}");
            AudioClip clip = await agent.GenerateSpeechAsync(testPhrase);
            agent.OutputAudioPlayer.Play(clip);
            
            // Wait for playback
            await UniTask.Delay((int)(clip.length * 1000) + 500);
        }
    }
}

2. Match Voice to Content

public Voice GetVoiceForContent(string content)
{
    // Story/narrative content
    if (content.Contains("Once upon a time") || content.Contains("story"))
    {
        return new Voice("fable");
    }
    // Tutorial/instructional
    else if (content.Contains("step") || content.Contains("tutorial"))
    {
        return new Voice("echo");
    }
    // Friendly conversation
    else
    {
        return new Voice("nova");
    }
}

3. Provide Speed Control

// Let users adjust speech speed
public class AccessibleSpeech : MonoBehaviour
{
    [SerializeField] private AgentBehaviour agent;
    
    [Header("Accessibility")]
    [SerializeField] private float defaultSpeed = 1.0f;
    [SerializeField] private bool allowSpeedControl = true;
    
    void Start()
    {
        // Load saved speed preference
        float savedSpeed = PlayerPrefs.GetFloat("SpeechSpeed", defaultSpeed);
        agent.Settings.OutputAudioParameters.Speed = savedSpeed;
    }
    
    public void SetSpeed(float speed)
    {
        if (!allowSpeedControl) return;
        
        agent.Settings.OutputAudioParameters.Speed = speed;
        PlayerPrefs.SetFloat("SpeechSpeed", speed);
    }
}

Complete Example

using UnityEngine;
using UnityEngine.UI;
using Glitch9.AIDevKit.Agents;
using TMPro;
using System.Linq;

public class VoiceManager : MonoBehaviour
{
    [SerializeField] private AgentBehaviour agent;
    
    [Header("UI")]
    [SerializeField] private TMP_Dropdown voiceDropdown;
    [SerializeField] private Slider speedSlider;
    [SerializeField] private TMP_Text speedText;
    [SerializeField] private Button previewButton;
    
    private string[] voices = { "alloy", "echo", "fable", "onyx", "nova", "shimmer" };
    private string[] descriptions = {
        "Neutral, balanced",
        "Male, clear",
        "British, expressive",
        "Deep male",
        "Female, friendly",
        "Female, warm"
    };
    
    void Start()
    {
        SetupVoiceDropdown();
        SetupSpeedSlider();
        
        previewButton.onClick.AddListener(PreviewCurrentVoice);
        
        // Load saved preferences
        LoadPreferences();
    }
    
    void SetupVoiceDropdown()
    {
        voiceDropdown.ClearOptions();
        
        var options = voices.Select((voice, i) => 
            $"{voice} - {descriptions[i]}"
        ).ToList();
        
        voiceDropdown.AddOptions(options);
        voiceDropdown.onValueChanged.AddListener(OnVoiceChanged);
    }
    
    void SetupSpeedSlider()
    {
        speedSlider.minValue = 0.5f;
        speedSlider.maxValue = 2.0f;
        speedSlider.value = 1.0f;
        speedSlider.onValueChanged.AddListener(OnSpeedChanged);
        
        UpdateSpeedText(1.0f);
    }
    
    void OnVoiceChanged(int index)
    {
        string voice = voices[index];
        agent.Voice = new Voice(voice);
        
        PlayerPrefs.SetString("PreferredVoice", voice);
        Debug.Log($"✓ Voice: {voice}");
    }
    
    void OnSpeedChanged(float speed)
    {
        agent.Settings.OutputAudioParameters.Speed = speed;
        UpdateSpeedText(speed);
        
        PlayerPrefs.SetFloat("SpeechSpeed", speed);
    }
    
    void UpdateSpeedText(float speed)
    {
        speedText.text = $"Speed: {speed:F2}x";
    }
    
    async void PreviewCurrentVoice()
    {
        previewButton.interactable = false;
        
        try
        {
            string previewText = $"Hello, I'm {agent.Voice.Id}. This is my voice at {agent.Settings.OutputAudioParameters.Speed:F1}x speed.";
            
            AudioClip clip = await agent.GenerateSpeechAsync(previewText);
            agent.OutputAudioPlayer.Play(clip);
            
            await UniTask.Delay((int)(clip.length * 1000));
        }
        finally
        {
            previewButton.interactable = true;
        }
    }
    
    void LoadPreferences()
    {
        // Load voice
        string savedVoice = PlayerPrefs.GetString("PreferredVoice", "alloy");
        int voiceIndex = System.Array.IndexOf(voices, savedVoice);
        if (voiceIndex >= 0)
        {
            voiceDropdown.value = voiceIndex;
        }
        
        // Load speed
        float savedSpeed = PlayerPrefs.GetFloat("SpeechSpeed", 1.0f);
        speedSlider.value = savedSpeed;
    }
}

Next Steps

PreviousModels NextTools & Tool Choice

Last updated 15 minutes ago

Overview

OpenAI Voices

Available Voices

Set Voice

Try All Voices

Voice Characteristics

OpenAI Voice Guide

Choose by Use Case

Voice Settings

Speech Parameters

Speed Control

Runtime Speed Adjustment

Voice Selection UI

Dropdown Menu

Voice Preview Buttons

Character Voices

Assign Voices to Characters

ElevenLabs Integration

Custom Voices

Voice Cloning

Voice Persistence

Save User Preference

Per-Agent Voices

Voice Quality

Model Selection

Audio Format

Best Practices

1. Test Voices for Your Use Case

2. Match Voice to Content

3. Provide Speed Control

Complete Example

Next Steps