Voice Settings

Voice settings control how your agent sounds. Choose from multiple voice providers, adjust speaking style, and fine-tune the audio experience.

Voice Providers

Retone supports two premium TTS providers:

Cartesia (Recommended)
ElevenLabs

Cartesia Sonic 3 offers:

Ultra-low latency (< 100ms)
Emotional expressiveness
Natural prosody
Speed and stability controls

Best for: Most use cases requiring natural conversation

Basic Settings

Voice Selection

Choose from available voices:

Click the Voice dropdown
Browse available voices by provider
Preview voices before selecting
Click to apply

Speed

Control speaking rate:

Value	Effect
0.5	Half speed (very slow)
0.8	Slightly slower
1.0	Normal speed
1.2	Slightly faster
2.0	Double speed (very fast)

For phone calls, 0.9-1.1 typically sounds most natural.

Volume

Output volume level (0-100):

Volume: 80  # Recommended for clear audio

Responsiveness

How quickly the agent starts speaking (1-10):

Value	Effect
1-3	Slower, more deliberate responses
4-6	Balanced (recommended)
7-10	Faster, may interrupt caller

Emotional Expression (Cartesia)

Cartesia Sonic 3 supports emotional speech:

Emotion Types

Emotion	When to Use
`neutral`	Professional, business contexts
`friendly`	Customer service, general conversations
`excited`	Sales, promotions, positive news
`sympathetic`	Handling complaints, showing empathy
`curious`	Asking questions, gathering information
`confident`	Assertions, recommendations

Intensity

Level	Effect
`low`	Subtle emotional undertone
`medium`	Noticeable but not exaggerated
`high`	Strong emotional expression

Emotion:
  Type: friendly
  Intensity: medium

Back-channeling

Natural acknowledgment sounds during conversation:

Back-channeling:
  Enabled: true
  Frequency: 5        # How often (0-10)
  Words:
    - "mm-hmm"
    - "I see"
    - "right"
    - "okay"
    - "got it"

When Back-channeling Triggers

During caller’s longer statements
At natural pauses
When caller shares information
To indicate active listening

Higher frequency (7-10) sounds very engaged but may feel excessive. Lower (1-3) is more subtle.

Pre-response Phrases

Filler phrases before AI generates a response:

Pre-response:
  Enabled: true
  Phrases:
    - "Let me check that for you..."
    - "One moment please..."
    - "Good question..."
    - "I can help with that..."

Benefits

Reduces perceived latency
Sounds more natural
Gives AI processing time

Conditional Pre-responses

Trigger different phrases based on context:

Conditions:
  - trigger: "complex_query"
    phrase: "Let me look into that..."
  - trigger: "simple_query"
    phrase: "Sure..."
  - trigger: "emotional"
    phrase: "I understand..."

Laughter Injection

Add natural laughter to appropriate moments:

Laughter:
  Enabled: true

When enabled, the AI may add subtle laughter in response to humorous comments from callers.

Pronunciation Overrides

Custom pronunciations for specific words:

Pronunciations:
  "Acme": "ACK-mee"
  "API": "A P I"
  "SQL": "sequel"
  "GIF": "jiff"
  "nginx": "engine-x"

Adding Pronunciations

Go to Voice Settings
Click Pronunciation Overrides
Add word and phonetic spelling
Test with voice preview

Auto-enabled Features

These settings are enabled by default:

Feature	Description
Allow interruptions	Caller can interrupt agent
Speech normalization	Numbers read naturally
Noise filtering	Background noise reduced
Background speech detection	Handles side conversations

Configuration Example

Complete voice configuration:

Voice Settings:
  Provider: Cartesia
  Voice: "Sonic 3 - Professional Male"
  Speed: 1.0
  Volume: 80
  Responsiveness: 5

  Emotion:
    Type: friendly
    Intensity: medium

  Back-channeling:
    Enabled: true
    Frequency: 5
    Words: ["mm-hmm", "I see", "right"]

  Pre-response:
    Enabled: true
    Phrases:
      - "Let me check..."
      - "One moment..."

  Pronunciations:
    "TechFlow": "TECH-flow"
    "API": "A P I"

Testing Voice Settings

Open the Test Call panel
Have a conversation with your agent
Listen for:
- Natural pacing
- Clear pronunciation
- Appropriate emotion
- Smooth back-channeling
Adjust settings and retest

Best Practices

Match Brand Voice

Choose a voice that fits your company’s personality.

Test on Phone

Audio sounds different on phone vs. computer. Test both.

Moderate Back-channeling

Too much feels robotic; too little feels distant.

Add Key Pronunciations

Ensure company names, products, and jargon sound correct.

System Prompt

Define agent personality

Environment

Background sounds and ambience

Test Call

Test voice settings

Getting Started

Agent Builder

Agent Configuration

Test Agent

Publish

Voice Providers

Basic Settings

Voice Selection

Speed

Volume

Responsiveness

Emotional Expression (Cartesia)

Emotion Types

Intensity

Back-channeling

When Back-channeling Triggers

Pre-response Phrases

Benefits

Conditional Pre-responses

Laughter Injection

Pronunciation Overrides

Adding Pronunciations

Auto-enabled Features

Configuration Example

Testing Voice Settings

Best Practices

Match Brand Voice

Test on Phone

Moderate Back-channeling

Add Key Pronunciations

System Prompt

Environment

Test Call

​Voice Providers

​Basic Settings

​Voice Selection

​Speed

​Volume

​Responsiveness

​Emotional Expression (Cartesia)

​Emotion Types

​Intensity

​Back-channeling

​When Back-channeling Triggers

​Pre-response Phrases

​Benefits

​Conditional Pre-responses

​Laughter Injection

​Pronunciation Overrides

​Adding Pronunciations

​Auto-enabled Features

​Configuration Example

​Testing Voice Settings

​Best Practices

Match Brand Voice

Test on Phone

Moderate Back-channeling

Add Key Pronunciations

​Related

System Prompt

Environment

Test Call

Voice Providers

Basic Settings

Voice Selection

Speed

Volume

Responsiveness

Emotional Expression (Cartesia)

Emotion Types

Intensity

Back-channeling

When Back-channeling Triggers

Pre-response Phrases

Benefits

Conditional Pre-responses

Laughter Injection

Pronunciation Overrides

Adding Pronunciations

Auto-enabled Features

Configuration Example

Testing Voice Settings

Best Practices

Related