16 Voice Tools That Turn Your AI Phone Agent Into an Enterprise Contact Center

Your AI Phone Agent Just Got 16 Superpowers

When we launched thinnestAI's voice platform, the pitch was simple: connect an AI agent to a phone number and let it handle calls. That core promise hasn't changed. What has changed is how much your agent can do on every call.

Today we're shipping 16 configurable voice tools that transform a basic AI phone bot into a full-featured enterprise contact center — without writing a single line of code. Every tool is a toggle in the Voice panel. Turn it on, configure it through a clean settings modal, and your agent gains a new capability instantly.

Here's the full breakdown.

Analytics & Monitoring

You can't improve what you don't measure. These four tools give you deep visibility into every conversation.

1. Call Summary & Transcript

Every call now generates a structured JSON summary automatically — powered by the same LLM that runs your agent. No separate transcription service. No manual review.

What you get after every call:

• One-paragraph conversation summary
• Caller intent classification
• Resolution status (resolved / unresolved / transferred)
• Key entities: names, dates, account numbers, products mentioned
• Action items and follow-ups
• Sentiment score on a 1–10 scale

You can override the default summary prompt with your own instructions to extract exactly the data your workflows need — whether that's a CRM update payload, a ticket creation body, or a compliance report.

2. Webhook Events

Push real-time call events to any HTTP endpoint. Build automations that react to calls as they happen.

9 event types available:

• call.started / call.answered / call.ended — lifecycle events
• user.speech / agent.speech — real-time transcript stream
• call.transferred — handoff notification
• dtmf.received — keypad input detected
• sentiment.alert — negative sentiment threshold crossed
• call.summary — post-call summary payload

All payloads are signed with HMAC-SHA256 using your secret key. Failed deliveries retry up to 3 times automatically. This is the glue that connects your voice agent to Salesforce, HubSpot, Zendesk, or any internal system.

3. Sentiment-Based Escalation

Not every caller is happy. Some are frustrated before the agent even speaks. Sentiment escalation monitors the emotional trajectory of the conversation in real-time and acts when things go south.

How it works: The agent analyzes the last N turns of the conversation (configurable — default is 3 turns). When the rolling sentiment score drops below your threshold, one of three actions fires automatically:

• Transfer: Warm-transfer to a human agent with full context
• Notify: Fire a webhook alert to your team (Slack, PagerDuty, etc.)
• Flag: Tag the call for post-call review without interrupting the conversation

This is the difference between "the AI handled it" and "the AI handled it, and when it couldn't, it escalated before the customer got angry enough to churn."

4. Call Tagging & Disposition

At the end of every call, the LLM classifies the conversation with tags from your predefined list. Out of the box, you get 8 tags: Sale, Support, Complaint, Information, Callback Needed, Escalated, Resolved, Unresolved. Add your own — industry-specific, department-specific, campaign-specific — and the LLM will use them.

Combined with call summaries and webhooks, this gives you a fully automated post-call workflow: tag the call, summarize it, push it to your CRM, and move on.

Voice Quality

The difference between "talking to a robot" and "talking to a person" often comes down to tiny details: pronunciation, pacing, warmth, the ability to fill silence naturally. These tools address all of it.

5. TTS Emotions & Expressiveness

This is the one that makes people do a double-take on demo calls. When enabled, your agent doesn't just say the right words — it says them the right way.

• Warm, friendly tone for greetings
• Empathetic acknowledgment when the caller is frustrated
• Confident reassurance during resolution
• Apologetic softness for service issues

TTS Emotions work with Cartesia Sonic and ElevenLabs voices. The LLM wraps emotional cues that the TTS engine interprets for intonation, pace, and emphasis. Other providers gracefully ignore the cues — no errors, just neutral delivery.

6. Pronunciation Dictionary

Every company has words that TTS engines butcher: product names, acronyms, founder names, technical jargon. The pronunciation dictionary lets you define exact replacements.

Examples:

• "Agno" → "AG-no" (not "ag-NO")
• "SQL" → "sequel"
• "GIF" → "jif" (we won't judge)
• "IEEE" → "I triple E"

Replacements are applied before text reaches the TTS engine. Works with every provider, every voice, every language.

7. Silence Fillers

When the LLM takes 2+ seconds to generate a response, silence on the line feels like the call dropped. Silence fillers inject natural bridge phrases: "Let me look that up for you," "One moment please," "Give me just a second."

You configure the delay threshold (default: 2 seconds) and the phrase list. The agent picks randomly, so it never sounds scripted. This single feature has measurably reduced caller hang-ups during complex lookups.

8. Greeting Variants (A/B Testing)

Your opening line sets the tone for the entire call. Greeting Variants let you A/B test different greetings with configurable weights. Run "Hi there, how can I help?" against "Welcome to [Company], what can I do for you today?" and track which one leads to higher resolution rates using your call summary and tagging data.

Call Management

Enterprise calls aren't simple Q&A. Callers need to be put on hold, verified, coached. These tools handle the operational reality of high-volume calling.

9. Hold / Mute / Resume

Sometimes the agent needs a moment — to call an API, look up records, or consult a knowledge base. Instead of awkward silence, it places the caller on hold with a configurable message ("Please hold for a moment"), mutes itself while processing, and resumes with another message ("Thank you for holding, I have your information now").

10. Call Whisper / Agent Coaching

Inject caller context into the agent's system prompt right before it answers. When a VIP customer calls, the agent already knows their name, account history, and priority level — before saying hello.

Template variables: {{caller_name}}, {{account_id}}, {{last_interaction}}, {{priority}}, plus any custom fields you pass via webhook.

This is the equivalent of a supervisor whispering "This is John from Acme Corp, he called last week about the billing issue" into a human agent's ear.

11. Caller Authentication

Before accessing sensitive information — account balances, personal data, medical records — verify the caller's identity. Four auth modes:

• PIN: "Please enter your 4-digit PIN"
• Date of Birth: "For verification, what is your date of birth?"
• Passphrase: "What is your security passphrase?"
• Custom: Your own verification prompt

After 3 failed attempts (configurable), the agent either ends the call, transfers to a human, or continues with limited access. BFSI, healthcare, and insurance teams: this is the feature you've been waiting for.

Intelligence

These features make your agent genuinely smarter over time.

12. Multilingual Auto-Switch

A caller starts in English and switches to Hindi mid-sentence. Your agent detects the switch, changes its STT engine to Hindi, swaps the TTS voice to a Hindi speaker, and continues the conversation without missing a beat. No restart, no "I'm sorry, I only speak English."

You configure a language-to-voice map: English → Deepgram Nova-2 + Cartesia Asteria, Hindi → Sarvam Saaras V3 + Bulbul V3, Spanish → Deepgram + ElevenLabs. The LLM calls a tool to switch, and the pipeline reconfigures mid-call.

For Indian deployments, pair this with our Sarvam AI integration for native support across 22+ Indian languages.

13. Conversational Memory (Cross-Call)

Your agent remembers. When a repeat caller dials in, the agent receives summaries from their last 5 calls (configurable) as additional context. "I see you called last Tuesday about a billing issue that was escalated to our team — let me check on the status of that."

Memory is matched by caller phone number and respects a configurable token budget (default: 500 tokens) to keep context relevant without blowing up latency.

14. Dynamic Speed/Pace Control

The agent adapts its speaking speed to the conversation context: slower for complex explanations, faster for simple confirmations, natural pauses at key moments. Works best with Cartesia and ElevenLabs TTS. Other providers receive implicit pacing through the LLM's word choice and punctuation.

15. Barge-In Phrases (Smart Interruption)

Not all interruptions are equal. "Stop" and "Wait" should always cut through. "Mmhmm" and "uh huh" should never trigger an interruption — they're backchanneling, not objections.

Barge-In Phrases lets you define two lists: Always Interrupt (urgent phrases that immediately stop the agent) and Never Interrupt (backchannel sounds that should be ignored). The result is an agent that listens when it should and stops when it must.

16. Business Hours / Time-of-Day Routing

Set your business hours by day of the week and timezone. During business hours, the agent operates normally. Outside business hours, it switches to a different greeting ("We're currently closed, but I can still help you or take a message") and can follow a different prompt — taking messages, scheduling callbacks, or providing limited self-service.

Everything Works Together

The real power isn't any single tool — it's the combinations.

• Sentiment Escalation + Call Summary + Webhook: When a frustrated caller is detected, auto-transfer to a human, generate a summary of what happened, and push the entire context to your CRM — before the human agent even picks up
• Caller Auth + Conversational Memory + Call Whisper: Verify the caller, load their history, and brief the agent on their last interaction — all before the first "How can I help you?"
• Multilingual + Greeting Variants + Silence Fillers: A/B test greetings in multiple languages, with natural filler phrases during processing — creating an experience that feels natively localized
• Call Tagging + Webhook + Business Hours: Auto-tag every after-hours call as "callback_needed" and push it to your team's morning queue

Each tool is a toggle. Mix, match, and configure through clean settings modals — no code, no deployment, no waiting.

Built for Enterprise, Priced for Everyone

Every tool is available on every plan, including the free tier. No per-feature pricing, no enterprise-only gates. Enable what you need and pay only for your call minutes.

Get Started

All 16 tools are live now. Open your agent's Voice panel, switch to the Tools tab, and start toggling. For detailed configuration guides, check our Voice Tools documentation.

Try All 16 Voice Tools Free →

No credit card required • All tools included • Deploy in minutes