Voice Output

Let NPCs speak their responses aloud with text-to-speech. Voice output is optional - LoreMindNPC works without it.

Providers

LoreMind supports two TTS providers:

Provider	Type	Cost	Quality	Latency
Kokoro	Local	FREE	High (#1 on HuggingFace)	~50-200ms
ElevenLabs	Cloud	Paid	Very High	~200-500ms

Recommendation:

Development/Testing: Use Kokoro (free, offline, no API costs)
Production: Either works - Kokoro is viable for PC/console, ElevenLabs for mobile/WebGL

Prerequisites

Kokoro (Local TTS)

Kokoro runs entirely on-device using the Kokoro-82M model (~80MB).

Install KokoroSharp NuGet package
Add LOREMIND_KOKORO scripting define symbol

ElevenLabs (Cloud TTS)

Create account at elevenlabs.io
Get API key from your dashboard
Enter API key in Window > LoreMind > Control Panel > Voice

Installation

1. Add Scripting Define (Kokoro only)

Go to Edit > Project Settings > Player
Expand Other Settings > Script Compilation
Add LOREMIND_KOKORO to Scripting Define Symbols
Click Apply

2. Enable in Project Settings

Open Window > LoreMind > Control Panel
Go to Voice tab
Enable Text-to-Speech
Select TTS Provider (Kokoro or ElevenLabs)
For ElevenLabs: Enter your API key

Quick Setup

Add the Component

Select your NPC GameObject (with LoreMindNPC)
Add Component > LoreMind > Voice > Voice Output

The component auto-adds an AudioSource for playback.

Enable Auto-Speak

The easiest way to use voice output:

On your LoreMindNPC, enable Auto-Speak Responses
Assign the Voice Output component

Now every NPC response is automatically spoken!

Manual Control

For more control, trigger speech from code:


using UnityEngine;
using Peek.LoreMind;
using Peek.LoreMind.Voice;
 
public class NPCVoiceDemo : MonoBehaviour
{
    [SerializeField] private LoreMindNPC npc;
    [SerializeField] private LoreMindVoiceOutput voiceOutput;
 
    void Start()
    {
        // Speak when NPC responds
        npc.OnResponseReceived.AddListener(response =>
        {
            voiceOutput.Speak(response);
        });
    }
}

Per-NPC Voice Configuration

Each NPC can have its own unique voice:


// Set voice in code
voiceOutput.VoiceId = "am_adam"; // Kokoro voice ID
 
// Or override provider for this NPC only
voiceOutput.OverrideProvider = true;
voiceOutput.ProviderOverride = TTSProviderType.ElevenLabs;

Kokoro Voices

Voice ID	Name	Accent	Gender
`af_bella`	Bella	American	Female
`af_nicole`	Nicole	American	Female
`af_sarah`	Sarah	American	Female
`af_sky`	Sky	American	Female
`am_adam`	Adam	American	Male
`am_michael`	Michael	American	Male
`bf_emma`	Emma	British	Female
`bf_isabella`	Isabella	British	Female
`bm_george`	George	British	Male
`bm_lewis`	Lewis	British	Male

ElevenLabs Voices

Voice IDs are fetched from your ElevenLabs account. Check the Voice Output inspector or call:


TTSVoiceInfo[] voices = voiceOutput.GetAvailableVoices();
foreach (var voice in voices)
{
    Debug.Log($"{voice.name}: {voice.id}");
}

Complete Example


using UnityEngine;
using UnityEngine.UI;
using Peek.LoreMind;
using Peek.LoreMind.Voice;
 
public class TalkingNPC : MonoBehaviour
{
    [SerializeField] private LoreMindNPC npc;
    [SerializeField] private LoreMindVoiceOutput voiceOutput;
 
    [Header("UI")]
    [SerializeField] private Text subtitleText;
    [SerializeField] private Image speakingIndicator;
 
    void Start()
    {
        // Configure voice
        voiceOutput.VoiceId = "am_adam"; // Male voice
 
        // Wire up voice events
        voiceOutput.OnSpeechStarted.AddListener(() =>
        {
            speakingIndicator.color = Color.green;
        });
 
        voiceOutput.OnSpeechCompleted.AddListener(() =>
        {
            speakingIndicator.color = Color.gray;
        });
 
        voiceOutput.OnError.AddListener(error =>
        {
            Debug.LogError($"TTS Error: {error}");
            speakingIndicator.color = Color.red;
        });
 
        // Show subtitles and speak
        npc.OnResponseReceived.AddListener(response =>
        {
            subtitleText.text = response;
            voiceOutput.Speak(response);
        });
    }
 
    // Public method for UI button
    public void StopSpeaking()
    {
        voiceOutput.Stop();
    }
}

Configuration

Playback Settings

Setting	Description	Default
Voice ID	Provider-specific voice identifier	(default)
Use Streaming	Start playback before synthesis completes	true
Speech Rate	Playback speed (0.5 = slow, 2.0 = fast)	1.0
Volume	Audio volume	1.0

Provider Override

Setting	Description	Default
Override Provider	Use different provider for this NPC	false
Provider Override	Provider to use when overriding	None

Events


// Speech lifecycle
voiceOutput.OnSpeechStarted.AddListener(() => ShowSpeakingUI());
voiceOutput.OnSpeechCompleted.AddListener(() => HideSpeakingUI());
 
// Error handling
voiceOutput.OnError.AddListener(error => ShowErrorMessage(error));

API Summary

Properties


bool IsSpeaking { get; }
bool IsSynthesizing { get; }
string LastSpokenText { get; }
AudioSource AudioSource { get; }
 
string VoiceId { get; set; }
bool OverrideProvider { get; set; }
TTSProviderType ProviderOverride { get; set; }

Methods


void Speak(string text)
Task SpeakAsync(string text)
void Stop()
TTSVoiceInfo[] GetAvailableVoices()
string GetProviderName()
Task ReinitializeProviderAsync()

Streaming vs Non-Streaming

Streaming (Default)

Audio starts playing while still being synthesized. Lower perceived latency.


voiceOutput.UseStreaming = true; // Inspector or code

Non-Streaming

Waits for complete audio before playing. Useful for short responses or when you need the full audio clip.


voiceOutput.UseStreaming = false;

Async/Await Pattern

For precise control over speech completion:


public async void HandleResponse(string response)
{
    // Wait for speech to complete
    await voiceOutput.SpeakAsync(response);
 
    // Speech finished, continue with next action
    ShowNextDialogueOption();
}

Combining Voice Input and Output

Create a full voice conversation loop:


using UnityEngine;
using Peek.LoreMind;
using Peek.LoreMind.Voice;
 
public class VoiceConversation : MonoBehaviour
{
    [SerializeField] private LoreMindNPC npc;
    [SerializeField] private LoreMindVoiceInput voiceInput;
    [SerializeField] private LoreMindVoiceOutput voiceOutput;
 
    void Start()
    {
        // Player speaks -> NPC responds -> NPC speaks
        voiceInput.OnTranscription.AddListener(playerText =>
        {
            npc.Respond(playerText);
        });
 
        npc.OnResponseReceived.AddListener(response =>
        {
            voiceOutput.Speak(response);
        });
    }
}

Troubleshooting

”TTS provider not available”

Check TTS is enabled in Control Panel > Voice
Verify scripting define (LOREMIND_KOKORO) is set
For ElevenLabs: Check API key is valid

No audio plays

Verify AudioSource component exists and is enabled
Check AudioSource volume is not zero
Check AudioListener exists in scene

First synthesis is slow

Kokoro loads the model on first use (~1-2 seconds). Subsequent calls are fast.


// Pre-warm at scene start
await voiceOutput.SpeakAsync(""); // Empty string, just initializes

Audio sounds choppy (streaming)

Try disabling streaming for this NPC:


voiceOutput.UseStreaming = false;

ElevenLabs rate limit

ElevenLabs has usage limits. If you hit rate limits:

Reduce speech frequency
Cache common responses
Consider Kokoro for development

Platform Support

Platform	Kokoro	ElevenLabs
Windows	Native	API
macOS	Native	API
Linux	Native	API
iOS/Android	Via ONNX	API
WebGL	Not supported	API

Best Practices

Provide Visual Feedback

Always indicate when the NPC is speaking:


voiceOutput.OnSpeechStarted.AddListener(() =>
{
    npcNameplate.color = Color.green;
    speakingBubble.SetActive(true);
});
 
voiceOutput.OnSpeechCompleted.AddListener(() =>
{
    npcNameplate.color = Color.white;
    speakingBubble.SetActive(false);
});

Show Subtitles

Not all players can use audio. Always show text:


npc.OnResponseReceived.AddListener(response =>
{
    subtitleText.text = response;
    voiceOutput.Speak(response);
});

Handle Interruptions

Let players skip or interrupt speech:


void Update()
{
    if (Input.GetKeyDown(KeyCode.Space) && voiceOutput.IsSpeaking)
    {
        voiceOutput.Stop();
    }
}

Different Voices for Different NPCs

Give each NPC character a unique voice:


// Gruff blacksmith - male British
blacksmithVoice.VoiceId = "bm_george";
 
// Young apprentice - female American
apprenticeVoice.VoiceId = "af_sky";
 
// Wise elder - male American
elderVoice.VoiceId = "am_adam";

Next Steps

Voice Input - Let players speak to NPCs
LoreMindNPC Component - Main component guide
API Reference - Complete API documentation