Text-to-Speech Integration

Available Providers

OpenAI (Recommended - Best Balance)

Why Choose OpenAI:

Natural sounding voices
Wide language support
Good cost structure
Easy setup (if already using GPT)

Quality: Excellent
Speed: 1-3 seconds to first audio
Cost: ~$0.015 per 1K characters
Languages: 50+
Voices: 5 options

ElevenLabs (Best Voice Quality)

Why Choose ElevenLabs:

Most natural sounding voices
Extensive voice library
Voice cloning available
Premium sound quality

Quality: Premium
Speed: 1-2 seconds
Cost: ~$0.03 per 1K characters
Languages: 30+
Voices: 100+ (including custom clones)

Cartesia (Enterprise Grade)

Why Choose Cartesia:

Studio-quality audio
Ultra-low latency
Extreme customization
Enterprise support

Quality: Studio
Speed: < 1 second
Cost: Custom pricing
Languages: 40+
Voices: Customizable

Rime AI (Fastest)

Why Choose Rime AI:

Fastest synthesis
Good quality
Real-time performance
Lower cost

Quality: Good
Speed: < 500ms (fastest)
Cost: ~$0.01 per 1K characters
Languages: 30+
Voices: 20+

Inworld AI (Character Voices)

Why Choose Inworld:

Character-specific voices
Interactive responses
Custom personality
Story-driven conversations

Quality: Good
Speed: 1-2 seconds
Cost: Custom pricing
Languages: 20+
Voices: Character personas

Provider Comparison

Feature	OpenAI	ElevenLabs	Cartesia	Rime AI
Voice Quality	⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐
Speed	⭐⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐⭐
Cost	⭐⭐⭐⭐	⭐⭐⭐	⭐⭐	⭐⭐⭐⭐⭐
Voices	⭐⭐⭐	⭐⭐⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐
Languages	⭐⭐⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐⭐	⭐⭐⭐⭐

Setup

OpenAI TTS Setup (Recommended)

Step 1: Get API Key If you’re already using OpenAI for LLM, you have everything needed.

Go to platform.openai.com/api-keys
Copy API key (or use existing)
Ensure TTS is enabled in account

Step 2: Add to CallIntel

Go to Settings → Developer Settings
Click “API Keys”
Select “OpenAI” from provider list (if not already added)
Paste API key
Save

Step 3: Configure Agent

Create/Edit Agent
Under “Text-to-Speech”, select:
- tts-1 (fastest)
- tts-1-hd (highest quality)
Choose voice:
- Alloy, Echo, Fable, Onyx, Nova, Shimmer
Select language
Adjust speed (0.25 - 4.0)
Save

Step 4: Test

Make a web call
Listen to voice quality
Adjust if needed

ElevenLabs Setup

Step 1: Create Account

Visit elevenlabs.io
Sign up for account
Verify email

Step 2: Get API Key

Go to Account Settings
Click “API Keys”
Copy your API Key
Save securely

Step 3: Add to CallIntel

Go to Settings → Developer Settings
Click “API Keys”
Select “ElevenLabs” from provider list
Paste API key
Click “Test Connection”
Save

Step 4: Configure Agent

Create/Edit Agent
Under “Text-to-Speech”, select “ElevenLabs”
Choose voice:
- Browse available voices
- Listen to samples
- Select favorite
Configure stability & clarity
Save

Step 5: Optional - Clone Your Voice To create custom voice:

Go to ElevenLabs dashboard
Click “Voice Lab”
Select “Clone Voice”
Record 30-120 seconds of your voice
ElevenLabs creates voice
Use in agents

Cartesia Setup

Step 1: Contact Sales

Visit cartesia.ai
Request enterprise access
Complete onboarding
Receive API credentials

Step 2: Configure in CallIntel

Go to Settings → Developer Settings
Add Cartesia API key
Configure for TTS
Save

Step 3: Configure Agent

Create/Edit Agent
Select Cartesia for TTS
Choose voice (provided by sales)
Configure quality settings
Save

Rime AI Setup

Step 1: Create Account

Visit rime.ai
Sign up for account
Verify email

Step 2: Get API Key

Go to Dashboard
Click “API Keys”
Create new key
Copy key

Step 3: Add to CallIntel

Go to Settings → Developer Settings
Select “Rime AI”
Paste API key
Save

Step 4: Configure Agent

Create/Edit Agent
Select “Rime AI” for TTS
Choose voice
Adjust speed and tone
Save

Cost Comparison

Monthly Costs (1000 calls, 2 min avg, 200 chars/min)

OpenAI (tts-1):
1000 calls × 2 min × 200 chars = 400,000 chars
400,000 × ($0.015/1000 chars) = $6/month
Cost per call: $0.006

ElevenLabs:
1000 calls × 2 min × 200 chars = 400,000 chars
400,000 × ($0.03/1000 chars) = $12/month
Cost per call: $0.012

Rime AI:
1000 calls × 2 min × 200 chars = 400,000 chars
400,000 × ($0.01/1000 chars) = $4/month
Cost per call: $0.004

Cartesia:
Custom pricing (typically enterprise rates)

Cost Ranking:

Rime AI (cheapest)
OpenAI (good value)
ElevenLabs (premium)
Cartesia (enterprise)

Voice Selection

OpenAI Voices

Voice	Gender	Style	Use Case
Alloy	Neutral	Professional	Customer service
Echo	Male	Clear	Sales, support
Fable	Narrative	Storytelling	Interactive scripts
Onyx	Male	Deep, warm	Executive calls
Nova	Female	Professional	General purpose
Shimmer	Female	Upbeat	Friendly service

Recommendation:

Customer service: Nova or Alloy
Sales: Echo
Executive: Onyx
Friendly tone: Shimmer

ElevenLabs Voice Selection

Browse 100+ voices by:

- Gender (male, female, neutral)
- Age (young, middle-aged, senior)
- Accent (American, British, etc.)
- Tone (friendly, professional, etc.)

Tips:

Listen to samples
Test with your script
Consider context
Select voice that matches brand

Custom Voice Cloning

Create voice that sounds like you:

Step 1: Record yourself (30-120 seconds)
Step 2: ElevenLabs processes audio
Step 3: Clone available for use
Step 4: Use in agents

Cost: Included with subscription
Quality: Premium
Use: Brand consistency

Configuration Options

Speed Control

Adjust how fast agent speaks:

5x = Very slow (for complex topics)
75x = Slow (for clarity)
0x = Normal (default)
25x = Fast (for efficiency)
5x = Very fast (for quick updates)

Recommendation: 1.0x for customer service

Voice Quality

OpenAI Quality Options:

tts-1: Faster, lower latency (50ms latency)
tts-1-hd: Higher quality audio (100ms latency)

Recommendation:
- Real-time calls: tts-1
- Pre-recorded calls: tts-1-hd

ElevenLabs Stability/Clarity:

Stability: 0-100 (lower = more variable)
Clarity: 0-100 (higher = more clear)

Balanced: Stability 50, Clarity 75
Natural: Stability 30, Clarity 75
Consistent: Stability 100, Clarity 75

Language & Accent

Most providers support multiple languages:

OpenAI: 50+ languages
ElevenLabs: 30+ languages
Rime AI: 30+ languages

Configuration:
1. Select language in agent settings
2. Choose appropriate voice
3. Test pronunciation
4. Save

Advanced Features

Voice Cloning (ElevenLabs)

Create custom voices:

Requirements:
- 30-120 seconds of clear audio
- No background noise
- Natural speaking voice
- 1-2 sentences recommended

Quality: Professional, realistic
Cost: Included in subscription
Use Cases: Brand consistency, CEO voice

Streaming Audio

Get audio as response generates:

Advantage: Start speaking immediately
Latency: Very low (< 500ms to first word)
Quality: Same as buffered
Cost: Same pricing
Best For: Real-time conversations

Emotion & Style Customization

Available through some providers:

OpenAI: Fixed emotions per voice
ElevenLabs: Variability control (emotion)
Rime AI: Emotion settings available

Use: Match tone to conversation context

Troubleshooting

Voice sounds robotic or unnatural

Try ElevenLabs for more natural sound, or adjust stability/clarity settings if using ElevenLabs.

Speech is too fast or too slow

Adjust speed setting (0.5x - 4.0x depending on provider).

Wrong pronunciation of company names

Provide phonetic guide to agent’s knowledge base, or use custom vocabulary feature if available.

Cost is higher than expected

Switch to Rime AI (lowest cost), or reduce character count by shortening responses.

Latency too high for real-time calls

Use tts-1 (not tts-1-hd) for OpenAI, or switch to Rime AI/Cartesia.

Best Practices

1. Start with OpenAI

Best balance of:
- Quality (natural sounding)
- Cost (reasonable)
- Languages (50+)
- Simplicity (integrated with GPT)

2. Test Multiple Voices

Create test agents with different voices
Make sample calls
Compare quality
Choose best for brand

3. Match Voice to Brand

Professional service: Nova or Alloy
Friendly service: Shimmer or custom
Technical support: Echo or Onyx
Sales: Nova (warm and professional)

4. Optimize Response Length

Shorter responses = Lower cost + Better experience
Keep responses under 200 characters
Use bullet points instead of paragraphs
Remove unnecessary words

5. Monitor Quality

Weekly Checks:
- Listen to sample calls
- Check pronunciation
- Verify speed
- Ensure consistency

Performance Tips

Real-Time Optimization

Configuration | Latency   | Quality
--------------|-----------|----------
OpenAI tts-1  | 50-100ms  | Good
Rime AI       | 50-150ms  | Good
Cartesia      | < 50ms    | Excellent
ElevenLabs    | 100-200ms | Excellent

Cost Optimization

Rank | Provider   | Cost/Call
-----|------------|----------
1    | Rime AI    | $0.004
2    | OpenAI     | $0.006
3    | ElevenLabs | $0.012
4    | Cartesia   | Enterprise

Quality Ranking

ElevenLabs (most natural)
Cartesia (studio quality)
OpenAI (professional)
Rime AI (good quality)

Speech-to-Text

Configure voice input

AI Models Overview

Compare all AI providers

Agent Setup

Create complete agents

Support

OpenAI TTS Docs

OpenAI Text-to-Speech

ElevenLabs Docs

ElevenLabs Documentation

Contact Support

Email: callintel01@gmail.com

​Available Providers

​OpenAI (Recommended - Best Balance)

​ElevenLabs (Best Voice Quality)

​Cartesia (Enterprise Grade)

​Rime AI (Fastest)

​Inworld AI (Character Voices)

​Provider Comparison

​Setup

​OpenAI TTS Setup (Recommended)

​ElevenLabs Setup

​Cartesia Setup

​Rime AI Setup

​Cost Comparison

​Monthly Costs (1000 calls, 2 min avg, 200 chars/min)

​Voice Selection

​OpenAI Voices

​ElevenLabs Voice Selection

​Custom Voice Cloning

​Configuration Options

​Speed Control

​Voice Quality

​Language & Accent

​Advanced Features

​Voice Cloning (ElevenLabs)

​Streaming Audio

​Emotion & Style Customization

​Troubleshooting

​Best Practices

​1. Start with OpenAI

​2. Test Multiple Voices

​3. Match Voice to Brand

​4. Optimize Response Length

​5. Monitor Quality

​Performance Tips

​Real-Time Optimization

​Cost Optimization

​Quality Ranking

​See Also