Voice AI

AI Voice Agent Development Company

Phone calls answered and placed by an agent that actually holds a conversation. It books, looks things up, updates your systems, and hands to a person the moment it should.

Trusted by teams worldwide

Connexate Meshmedia Oaky Setia Haruman Wave Sugar
What We Build

Voice Agents, End to End

Voice is unforgiving. A caller hears every pause and every wrong turn, so most of the work is in the parts nobody demos. Assistants that answer in text belong with AI chatbot development.

01

Call Flow Design

  • We map the calls you actually get, from your recordings and your team
  • Intents scoped to what the agent can finish, not what it can recognise
  • Failure paths designed first, because that is where callers are lost
02

Inbound Voice Agents

  • Answers every call, including the ones that ring out at peak
  • Resolves the routine ones end to end instead of routing them onward
  • Escalates with the transcript attached, so nobody repeats themselves
03

Outbound Voice Agents

  • Reminders, confirmations, follow-ups and qualification calls
  • Consent and opt-out handled as a requirement, not an afterthought
  • Calling windows and retry rules respected per jurisdiction
04

IVR Replacement

  • Open speech instead of press 1, press 2
  • Handles the callers who used to press 0 to escape the menu
  • Runs alongside the existing IVR first, so cutover is not a leap
05

Appointment Booking

  • Checks real availability rather than promising a callback
  • Books, reschedules and cancels straight into the calendar or EHR
  • Confirmations by SMS or email, written back to the record
06

Telephony Integration

  • Works with your existing numbers, SIP trunks and call centre
  • Warm and cold transfer to a human queue
  • Call recording and retention configured to your policy
07

CRM & Systems Integration

  • Reads the caller's real account so it can discuss specifics
  • Writes outcomes back, so the call is not retyped later
  • Covered in our voice CRM integration guide
08

Multilingual Voice

  • Speech recognition and synthesis chosen per language, not per vendor
  • Tested against accented speech from the markets you serve
  • Language detected in the call rather than asked for up front
09

Evaluation & Guardrails

  • A scored test set built from real calls before launch
  • Topic limits, refusal behaviour and mandatory escalation triggers
  • Disclosure that the caller is speaking to AI, stated at the start
10

Post-Launch Tuning

  • Transcripts reviewed for what went unanswered and where handover happened
  • Prompt, intent and routing changes shipped against real call data
  • An admin view so your team owns it rather than depending on us
Capabilities

Built for Real Callers

The difference between a demo and a deployment is almost entirely in these six.

Natural Turn-Taking

Callers interrupt, trail off and change their mind mid-sentence. We tune barge-in and end-of-speech detection for that, because an agent that talks over people is worse than a menu.

Barge-inInterruptionEnd-of-speech

Understands Intent

Speech becomes an intent and a set of parameters, not a keyword match. The caller says it their way and the agent still gets to the right task.

Open speechNo keywordsContext kept

Takes Action

Checking a calendar, booking a slot, looking up an order, updating a record. Answering is the easy half; completing the task is what removes the call from a human queue.

BookingLookupsWrite-back

Knows When to Hand Over

Confidence thresholds, sensitive topics and frustrated callers all trigger a transfer, with context attached. Knowing when to stop is a feature.

Warm transferContext passedHard triggers

Compliance-Aware

Disclosure, consent capture, retention limits and audit trails agreed before build. In regulated calls these are requirements, not settings to add later.

DisclosureConsentAudit trail

Measured, Not Guessed

Containment, handover rate, task completion and what callers asked that nobody anticipated. Quality becomes a number you can act on.

ContainmentQA scoringCall analytics
Agent Types

Types of AI Voice Agents We Build

Most projects are one of these eight. The right one is usually obvious once the call recordings are on the table.

01

Reception & Call Answering

  • Answers every call, including overflow and out of hours
  • Routes what it cannot finish, with context
  • Removes the ring-out at peak
02

Appointment Booking

  • Checks live availability and books
  • Reschedules and cancels
  • Sends confirmations and reminders
03

Customer Support Agents

  • Order status, account and billing questions
  • Answers from your approved content
  • Escalates on confidence or sentiment
04

Lead Qualification

  • Qualifies against your criteria, not a generic script
  • Books the qualified ones into a calendar
  • Writes the disqualified reason back to CRM
05

Outbound Reminders & Follow-ups

  • Appointment and payment reminders
  • Post-service follow-up calls
  • Consent, opt-out and calling windows enforced
06

IVR Replacement

  • Open speech instead of a keypad tree
  • Runs alongside the old IVR during cutover
  • Ends the press-0-to-escape habit
07

Internal Helpdesk Voice

  • Answers staff questions from SOPs and policies
  • Respects existing permissions
  • Cuts repetitive internal calls
08

Multilingual Voice Agents

  • Language detected in-call, not asked for
  • Per-language speech models
  • Tested on accented speech from your markets
How It Works

What Happens During a Call

Each turn is a full round trip, repeated for the length of the call. Our guide to building an AI voice agent goes deeper.

Caller speaksphone or web Speech to textwith barge-in Model + toolsbooks, looks up, writes Text to speechnatural cadence Agent repliesor hands over
Scroll the diagram to see all five steps. Every loop of this runs while the caller is still on the line, which is why turn-taking matters more than raw speed.
01

Where projects go wrong

  • Latency budget spent on a model that was never the bottleneck
  • No barge-in, so the agent talks over the caller
  • Nothing to hand over to when the agent is stuck
02

What we do differently

  • The call flow is designed from your recordings, not a template
  • Escalation is built before the happy path is polished
  • Every release is scored against a test set of real calls
03

Why voice is harder than chat

  • No backspace: a wrong turn is heard, not skimmed
  • Accents, background noise and crosstalk are the normal case
  • Common failure modes are catalogued in why voice agents fail
Free Call Flow Review

Not Sure Which Calls to Automate? Start There.

Send us a week of call reasons, or just describe what your team answers all day. We will tell you which calls a voice agent should take, which it should never take, and what has to exist before either is true.

Request Your Call Flow Review

Free · No obligation · Findings are yours to keep

Planning an AI voice agent project with Appther
Our Process

From First Recording to Live Calls

Five phases. The listening phase is the one people want to skip and the one that decides the outcome.

1
Phase 1

Listen

We go through real call recordings and reasons with your team, and agree which intents are in scope and which are explicitly out.

2
Phase 2

Design

Call flow, escalation rules, disclosure wording, data handling and the success measure, agreed before anything is built.

3
Phase 3

Pilot

One intent on one number, running alongside your existing setup, so the runbook is proven on something low-risk.

4
Phase 4

Launch

Rolled out intent by intent with a human queue behind it, and a rollback path kept open throughout.

5
Phase 5

Tune

Transcripts reviewed against the test set, prompts and routing adjusted, then handover to your team.

Measurable Impact

Numbers From a Shipped Voice Agent

Figures below come from one named, published deployment rather than a blended average.

70%

Front-desk call load removed

Reported in our healthcare voice agent deployment.

38%

Calls unanswered at peak, before

The starting position in that same deployment, which is what the agent was built to fix.

24/7

Every call answered

No queue, no voicemail and no out-of-hours gap.

12+

Countries served

Across Appther's delivery, with voice tuned per market and language.

Tech Stack

The Stack Behind Our Voice Agents

Chosen per deployment. Speech vendors in particular are picked per language rather than standardised for convenience, and we will say so when a simpler tool is the right answer.

OpenAIStreaming conversation model
Anthropic logo
ClaudeAlternative reasoning model
Gemini logo
GeminiMultilingual conversation
ElevenLabs logo
ElevenLabsNatural text-to-speech
TwilioTelephony and SIP trunking
LangChain logo
LangChainTool calling and retrieval
Python logo
PythonAgent orchestration layer
FastAPI logo
FastAPIRealtime API backend
PostgreSQL logo
PostgreSQLTranscripts and call logs
aws
AWSCloud infrastructure
Industries

Voice Agents Across Your Vertical

The same agent behaves very differently by sector. These are the calls each one usually automates first.

01

Healthcare Voice Agents

Patient intake, booking and rescheduling, without touching clinical advice.

  • Appointment booking into the EHR
  • Reminders and no-show reduction
  • Consent and retention handled up front
02

Banking & Fintech

Account and card calls inside strict authentication and audit requirements.

  • Caller verification before account detail
  • Balance, card and transaction queries
  • Every call logged for audit
03

Retail & eCommerce

Order and returns calls answered from live order data.

  • Where is my order, answered instantly
  • Returns and exchange handling
  • Peak-season overflow absorbed
04

Real Estate

Enquiry qualification and viewing booking outside office hours.

  • Qualifies buyers and renters
  • Books viewings into agent calendars
  • Answers listing and area questions
05

Education

Admissions and student services calls at the times they actually spike.

  • Course and admissions enquiries
  • Enrolment, fees and timetable questions
  • Term-start overflow handled
06

Logistics & Field Service

Delivery status and scheduling calls, plus support for drivers and technicians.

  • Delivery status and rescheduling
  • Job dispatch confirmations
  • Driver and field-team callbacks
Investment

How Much Does an AI Voice Agent Cost?

Any number quoted before the call flow is understood is a guess. These are the things that actually move it. For worked ranges see our voice agent cost breakdown.

01

What drives the number

  • Call volume, because voice carries a per-minute cost that chat does not
  • Inbound only, or outbound as well
  • How many systems the agent has to read and write
  • Languages, and how many speech vendors that implies
02

What gets underestimated

  • Preparing call flows from real recordings, usually the longest task
  • Evaluation, so quality is measured rather than felt
  • Telephony work: numbers, trunks, transfer paths
  • Tuning in the weeks after launch
03

How projects usually group

  • A single-intent agent on one number, such as booking
  • A multi-intent inbound agent with CRM and calendar integration
  • An enterprise or regulated deployment with auth, residency and audit
Get a Voice Agent Estimate
Client Voices

Trusted By Teams Who Ship

“Appther built our student competition app exactly the way we envisioned it: easy registration, smooth judging, and real-time results that keep participants engaged.”
Dionna Milem
Dionna MilemOwner · My BOB Team LLC
“Building a mental health app means every detail has to be handled with care, and Appther got that from day one. The product feels warm, simple, and genuinely helpful.”
Bob Singhal
Bob SinghalProfessor of Joy · Joyscore Inc
“Appther exceeded every expectation, on time and on budget, and the final product has been instrumental in scaling our business. A rare engineering partner.”
Johnathan Peffer
Johnathan PefferCEO · Bull's Eye Technologies Inc
“Implementing an ERP across our operations felt daunting at first, but Appther made the transition seamless. Every department now works off a single source of truth.”
Pushpender Kumar
Pushpender KumarGeneral Manager · AB Sugar Ltd
Latest Insights

Notes on Building Voice Agents

Field notes from real deployments. No hype, just what worked and what didn't.

All Articles

The Best Voice Agents Start With Your Actual Calls.

Tell us what your team answers all day and we will tell you what a voice agent should take, what it should never take, and what has to be true before either works.

FAQ

Questions We Hear Every Week

An AI voice agent answers or places phone calls and holds a real conversation rather than reading a menu. It understands what the caller said, decides what to do, acts on your systems (booking, looking up an order, updating a record) and speaks back. Unlike an IVR it does not need the caller to know the right keyword or press the right number.
An IVR is a decision tree: press 1, press 2, and anything unanticipated dead-ends. A voice agent handles open speech, interruptions, accents and people who change their mind mid-sentence, and it can complete the task instead of routing to whoever can. Most projects we take on are replacing an IVR that customers have learned to bypass by pressing 0.
Yes, and they should. We disclose it at the start of the call. Trying to pass an agent off as human damages trust the moment it slips, and in several jurisdictions disclosure is a legal requirement rather than a courtesy.
It hands over to a person, with the transcript and the caller's context attached so nobody is asked to repeat themselves. We set the escalation rules with you, including hard triggers such as a distressed caller, a compliance-sensitive topic, or repeated failure to understand.
That is the most common request. We connect the agent to your calendar, CRM and booking system behind your own authentication, so it can check real availability, book, reschedule and write the call outcome back. Our guide to voice assistant CRM integration walks through Salesforce, HubSpot and Odoo.
It depends on call volume, how many systems the agent touches, whether it is inbound only or also outbound, and the languages involved. Telephony and model usage are ongoing per-minute costs, which is what separates voice from a text chatbot commercially. Our voice agent cost breakdown covers MVP versus enterprise scope.
A focused single-intent agent, such as appointment booking on one number, is usually weeks. A multi-intent agent across several lines with deep integration runs longer. The tuning period after go-live matters as much as the build, because real callers do things no script anticipated.
Turn-taking is the hard part, not raw speed. We tune for interruption handling, barge-in and end-of-speech detection, because a caller talking over the agent is normal rather than an edge case. Latency targets are agreed per deployment against your telephony setup rather than promised up front.
Yes. We select speech recognition and synthesis per language rather than assuming one vendor covers all of them well, and we test with accented speech from the markets you actually serve, which is where most multilingual deployments fall over.
It can be, with the right controls. Our healthcare voice agent case study covers a HIPAA-oriented deployment for patient intake and booking. Regulated work needs consent capture, retention rules, access control and audit trails agreed before build, not retrofitted.
An Engineer Replies Within One Business Day

Let's Build Your AI Chatbot

Tell us what you want your chatbot to do. No sales pitch, just a straight answer on scope, timeline and cost.

Free 30-min strategy callScoping and honest, practical advice.
Fixed-price quoteDetailed scope and price after discovery, no surprises.
NDA on requestYour idea and code always stay yours.
Prefer to talk now?+91 99114 32288 · sales@appther.com

Book Your Free Strategy Call

Fields marked * are required. We reply within one business day.

🔒 Your details are never shared. NDA available on request.